History Main / SongsInTheKeyOfLock

* In one issue of ''WesternAnimation/MuppetBabies'', the group imagines that the world is running out of music. In their imaginations, it turns out that it's being eaten by the Note-All, with approval from Piggy, who wants ''her'' music to be all there is. His ''staff'' puts the ''rest'' behind ''bars''. When the Note-All eats Piggy's singing, as well, she decides to go free her friends. When physical keys don't unlock the bars, Rowlf suggests a ''musical'' key. When Piggy hits high C, the bars open.

* ''Series/StarTrekTheOriginalSeries'' episode "The Paradise Syndrome". The obelisk left by the {{Pre|cursors}}servers had a door that opened in response to a specific sequence of sounds (musical notes or speech tones).

* ''VideoGame/NancyDrew:The Deadly Device'' includes a puzzle where you have to first build a circuit board for a small tesla coil, and then program it to play a series of notes [[spoiler: revealed in Niko's notebook]]. Amusingly, you get an award for making the coil play actual music. Bonus points that this is a real life thing, called a "Zeusaphone".

* The Selenitic Age Descriptive Book in ''VideoGame/{{Myst}}'' is accessed via a five-note combination. Then to enter TheMaze, you have to play the five ambient sounds in the proper order. Furthermore, the sounds in the maze indicate the compass direction you need to go.

* ''Series/StarTrekPicard'': In a callback to "[[Recap/StarTrekTheNextGenerationS1E1EncounterAtFarpoint Encounter At Far point]]", [[spoiler:Moriarty]] is deactivated by whistling "Pop Goes The Weasel".

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[[quoteright:275:[[ComicBook/DisneyDucksComicUniverse https://static.tvtropes.org/pmwiki/pub/images/bonnie_4.png]]]]
[[caption-width-right:275:If you're tone-deaf, you're out of luck.]]

* The main objective in ''VideoGame/ImpossibleMission II'' is to collect six pieces of a song (two of the eight pieces are duplicates) that unlocks the express elevator to the penthouse control room.
* Several times in the ''VideoGame/{{Ultima}}'' series, the Avatar has to play a simplified version of the song 'Stones' in order to gain a PlotCoupon or MacGuffin.
* ''VideoGame/TheJourneymanProject 3'' has a set of Buddhist Prayer Wheels on which the player must playt a prayer chant. [[spoiler:One of them is squeaky and must be oiled first.]]
* ''VideoGame/SchizmMysteriousJourney'' runs in a similar vein as the above, with a set of Argilan prayer grinders. After an alien priest shows up and speaks a string of words that open a hidden door, you have to play it back using these devices.
* ''VideoGame/AlidaTheEnigmaticGiant'': Vaults scattered around the island are fitted with sensitive microphones which pick up the sound from the island's massive, fully functional electric guitar. Each and every component of the guitar must be set correctly - and that includes the peghead, switch, and potentiometer dials, before the guitar's sound can open the doors, provided a designated door has been primed to receive the sound, that is. The same game also has a small keyboard of tubular bells that unlocks the tram to the Switch.
* ''VideoGame/NancyDrew:The Deadly Device'' includes a puzzle where you have to first build a circuit board for a small tesla coil, and then program it to play a series of notes [[spoiler: revealed in Niko's notebook]]. Amusingly, you get an award for making the coil play actual music. Bonus points that this is a real life thing, called a "Zeusaphone".
* ''VideoGame/{{Safecracker}}'' has a fairly easy puzzle in the Crabb & Sons mansion/office's music room, used to unlock a well-hidden safe inside a piano. The code is the first 14 notes of Twinkle Twinkle Little Star.
* An optional puzzle in ''VideoGame/{{Undertale}}'' features this, where you must play the first few notes of a tune heard in a room a little bit ahead on a piano. [[spoiler:The reward's only barely worth it, though.]]
* ''VisualNovel/NineHoursNinePersonsNineDoors'': Unlocking the exit door to the First Class Cabin requires playing a piano. After collecting the sheet music, it's revealed that the piano is tuned incorrectly, so the actual puzzle is matching the proper notes to their altered locations. It's actually one of the easiest puzzles in the game, as the set of keys you're able to choose from is quite small, and after playing the first line correctly, the game completes the rest of the song for you. Notable in that the piece of music played isn't a character theme, scare chord, or in any way related to the game's soundtrack, but the Westminster Chimes. This prompts a comment from one of your companions as to Zero's motives and nothing else.
* Getting through one BonusDungeon in ''VideoGame/CosmicStarHeroine'' requires playing a sequence of notes on a piano. In practice this is a simple LockAndKeyPuzzle as you don't personally choose any notes, you simply need to find a piece of paper and then get to the piano.
* ''VideoGame/SacredEarthPromise'': The harpies in Fimbulvetir Forest set up doors that can only be opened by musical plants to play a specific sequence of notes. The forest also contains an underground ruin where the player has to go through the exits of a looping room in a specific order based on the notes that are made upon passing through.
* ''VideoGame/StarFoxAdventures'': Despite its strong inspiration in ''The Legend of Zelda'' games, the trope only occurs once in this game. After Fox retrieves the Gold Fruit to its owner in [=SnowHorn=] Wastes, he initiates a test where he has to play the Dinosaur Horn while standing on pads located strategically in key parts of the region, and do so before time runs out (it's recommended to clear the associated paths before starting to save time later). Once he succeeds, the gate to the next [[MiniDungeon Krazoa Shrine]] opens.
* ''VideoGame/LuigisMansion3'': One of the collectible gems is unlocked by using the air from Luigi's [[WeaponsThatSuck Poltergust]] to play the franchise's main melody on a group of bottles.

[[folder:Anime and Manga]]

* In a ''[[ComicBook/DisneyDucksComicUniverse Scrooge McDuck]]'' story by Creator/CarlBarks that's a riff on ''Literature/TheHunchbackOfNotreDame'', Scrooge programs his vault so that it can only be opened by playing "My Bonnie Lies over the Ocean". Trying to protect his secret by using a wishing well (ItMakesSenseInContext), he inadvertently reveals it to the hunchback (who lives near the bottom of the well scooping up the coins people throw in and eavesdropping on their wishes in the process), which kicks off the plot.
** A ''WesternAnimation/DuckTales1987'' comic written for ''Magazine/DisneyAdventures'' had a similar plot, in which Scrooge has a voice-activated lock to the vault on his money bin which only opens when it hears him singing the opening lines of "Comin' Through the Rye". And the Beagle Boys just so happen to have a cousin, Baritone Beagle, who's good at impressions...

* One shows up in Creator/WarrenEllis' ''Comicbook/IgnitionCity'', triggered by the owner's favorite song - "[[https://www.youtube.com/watch?v=kyofs0mreCc A Nightingale Sang In Berkeley Square]]".
* In the 60s ComicBook/{{Archie}} story "That Way Out Sound", Mr. Lodge shows off a vault with a door that can only be opened by the "unearthly, weird, way-out sound" produced by a one-of-a-kind tuning fork. Unfortunately, Archie accidentally locks him inside the vault, tuning fork included. A variant ensues as Archie and his friends free him by reproducing the "way-out sound" with their rock band instruments; it turns out there's no sound the Archies ''don't'' hit sooner or later.

[[folder:Films -- Animated]]

* ''WesternAnimation/DespicableMe2'': The entrance to El Macho's lair is protected by the tune of "La Cucaracha." HilarityEnsues as Gru tries to play the tune and his nacho sombrero hinders him every step of the way.

** In ''Film/ForYourEyesOnly'', the Identigraph room in Q's lab has a musical lock. The 7-note key is the title passage of "Nobody Does It Better" from ''Film/TheSpyWhoLovedMe'' (2 films earlier); it is less obvious, though, because Q stops after 5 notes and Film/JamesBond fills in the final 2 a few seconds later.
* In ''Film/TheGoonies'', a creepy pirate organ opens a door or collapses the floor depending on whether you play the right tune or not.
* In ''Film/BatmanBegins'', the Batcave is accessed from Wayne Manor by playing a specific sequence of keys on the piano. This is carried over to ''Film/TheDarkKnightRises''. It does not, however, happen in ''Film/TheDarkKnight''; a different "Batcave" is in use in that film, due to Wayne Manor being under reconstruction.
* ''Film/WillyWonkaAndTheChocolateFactory''. In Willy Wonka's factory, the door to enter the Chocolate Room (with the chocolate river) had a musical lock. The tune for the lock is the Overture from "The Marriage of Figaro," by Mozart, ''not'' Rachmaninoff, as [[KnowNothingKnowItAll Mrs. Teevee]] claims.

* In ''Film/HudsonHawk'', the villains use a ridiculous-looking set of handcuffs with colour- and sound-coded buttons. Which makes it trivial for Hawk to get out of them (in fairness, it's probable that they intended him to escape eventually).
* In ''Film/{{Prometheus}}'', the Engineers' ship is activated by pressing buttons in order and by playing notes on a flute-like instrument.
* In ''Film/Paddington2'', Madame Kozlova's fortune is hidden in a secret compartment inside a fairground organ which unlocks when a specific series of notes is played.

* In ''Literature/TheMouseWatch'', [[BigBad Dr. Thornpaw]] captures and imprisons several of the titular heroes. Bernie and her teammates figure out that Thornpaw is using a musical lock, and then Bernie realizes that the solution is to sing "Three Blind Mice".

* ''Series/Titans2018''. Near the end of season one, Dick Grayson [[ItMakesSenseInContext goes into an extended dream sequence]] about returning to Wayne Manor. He accesses the Bat Cave from one room by playing a sequence on the piano; possibly a ShoutOut to the ''Film/BatmanBegins'' and ''Film/TheDarkKnightRises'' examples in the Live Action Film section.

* ''VideoGame/ResidentEvil'' has a piano you play Beethoven's "Moonlight Sonata" on to unlock something. Jill knows piano; Chris has to find Rebecca.
* At one point in ''VideoGame/TheNeverhood'', you have to open a door by spitting into a series of tubes to make them whistle the same tune as another series of tubes.
* ''Franchise/TheLegendOfZelda'':
** ''VideoGame/TheLegendOfZeldaOcarinaOfTime'': Just as when its predecessors in the franchise often removed something barring your progress (except in ''A Link to the Past''), Link's ocarina can be used for the same purpose. Zelda's Lullaby will trigger mechanisms if Link [[PlatformActivatedAbility stands on "the Crest of the Royal Family" a.k.a. the Triforce]]; the Song Of Time removes and summons blocks with the Door Of Time's design on it, starting with the Door Of Time itself; and the Song Of Storms opens up the Bottom Of The Well.
** ''VideoGame/TheLegendOfZeldaMajorasMask'': Each of the four temples in Termina requires playing a specific song to open its entrance (or, in one case, simply reach it): "Sonata of Awakening" for Woodfall Temple, "Goron Lullaby" for Snowhead Temple, "New Wave Bossa Nova" for Great Bay Temple, and "Elegy of Emptiness" for Stone Tower Temple. This contrasts the temple songs from ''Ocarina of Time'', which simply [[WarpWhistle warped you to the temples' whereabouts]].
** ''VideoGame/TheLegendOfZeldaTheWindWaker'': The two temples whose sages empower the Master Sword require Link using the eponymous baton to conduct sacred melodies onto the newly-elected sages so they can open the temples' entrances, as well as inner parts afterward: "Earth God's Lyric" for Earth Temple and "Wind God's Aria" for Wind Temple. Notably, these two songs also make up for the game's title screen theme as well as the credits music.
** ''VideoGame/TheLegendOfZeldaSpiritTracks'': The Spirit Flute, which utilizes the DS microphone, has magical properties enabled with the songs learned. Playing duets with the Lokomos help restore the Spirit Tracks, which enable you to go to new areas.
** ''VideoGame/TheLegendOfZeldaSkywardSword'': The "Ballad of the Goddess", when played with the Goddess Harp, activates and opens the Gate of Time in Faron Province. The following three melodies open the entrance spot to the Silent Realm areas for the mainlands of the surface, tailored for the chosen hero. The last melody ("Song of the Hero") grants access to [[spoiler:the Silent Realm area of Skyloft and also holds the key to unlock the final dungeon in the game]].
** ''VideoGame/TheLegendOfZeldaBreathOfTheWild'': Compared to previous games, the game has a reduced presence of this trope. One of the [[MiniDungeon Ancient Shrines]], located in an area close to Rito Village in Tabantha, requires a quintet of Rito girls to sing in a specific order (and be assisted by Link waving a Korok Leaf to bring wind onto holey stones) in order to erect it.
* ''VideoGame/PrinceOfPersiaTheSandsOfTime''. In the GBA version, there are several levels that are passed by playing a certain tune in a certain sequence.
* In ''VideoGame/FinalFantasyII'', the entrance to Kashuan Keep can only be opened by the voice of a member of Kashuan's royal family or the ringing of the Goddess's Bell.
** ''VideoGame/FinalFantasyVII'' has the final LimitBreak for Tifa that is obtained by playing the right notes on the piano.
** ''VideoGame/FinalFantasyVIII'' has an organ that needs to be played to open a gate.
** A dungeon in ''VideoGame/FinalFantasyIX'' has bells as InterchangeableAntimatterKeys.
** ''VideoGame/FinalFantasyX2'' has a puzzle involving repeating notes.

* In ''VideoGame/{{Outcast}}'' you had to put the right pipes (as in flute pipe) into the right sockets on an altar (or something) to play a certain melody. After accomplishing this, you'd get another key for something else...
* The Selenitic Age Descriptive Book in ''VideoGame/{{Myst}}'' is accessed via a five-note combination. Then to enter TheMaze, you have to play the five ambient sounds in the proper order. Furthermore, the sounds in the maze indicate the compass direction you need to go.
** All the ''Myst'' games seem to have at least one sound puzzle each. In ''VideoGame/{{Riven}},'' the combination to unlock Catherine's cell is revealed by listening to [[spoiler:Gehn's watch]].
** ''Riven'' also has the overarching animal-sounds puzzle that is scattered across the islands. There are five balls with a D'ni number carved in them, and each makes a Riven animal sound when spun (using at least one fictional animal.) The code makes perfect sense, as it would only be understandable by someone well-versed in both Riven and D'ni culture (it was intended for Atrus, but the player [[GuideDangIt will figure it out eventually]].)
** ''VideoGame/MystIVRevelation'' involves using Sirrus' Spider Throne to vibrate four different pieces of minerals, so that all of them being pushed out of their literal "locks" deploys a bridge [[spoiler: to a bomb factory.]] The musical element comes from the tones Spire's crystals give off when their electrical charge fades, which the Throne channels via huge cables within the Age.
* The drawbridge passtune in ''VideoGame/NetHack''. You find it out by either playing Mastermind or by having your god tell it to you.
* ''VideoGame/{{Loom}}'s'' MagicMusic starts you off with the "Opening" draft, which works as a universal one of these (where [[ThePasswordIsAlwaysSwordfish The Password Is Always]] E-C-E-D).
* There are a couple of puzzles in ''VideoGame/LufiaIIRiseOfTheSinistrals'' where you have to step on "musical note" tiles in a certain order to open the locked doors.
* ''VideoGame/{{Startropics}}'' has a giant organ with eight keys, representing the notes of a musical scale. The solution comes from a parrot that says "Do me so far, do me?" This, of course, means playing "Do Mi So Fa Do Mi" on the organ.
* ''VideoGame/WonderBoyInMonsterWorld'' requires you to remember short ocarina sequences to open the doors in the first dungeon.
* ''VideoGame/EternalDarkness: Sanity's Requiem'' has you play one song three times: twice on an organ, once on a piano.
* ''VideoGame/TheSeventhGuest'' has one [[https://www.youtube.com/watch?v=9nSDedyBnzg&feature=search shown here]] involving a piano. Technically, though, it's more of a [[SimonSaysMinigame Simon Says puzzle]] in this case.
* One of the adventure games in the ''Trapped'' series (not ''VideoGame/TheTrappedTrilogy'', the ''VideoGame/TrappedSeries'') requires you to play the tune from a music box on the piano to open a secret door.
* Such a puzzle exists in ''VideoGame/SilentHill1'', the only clue being a poem about birds (and interestingly, the correct solution produces no music because the keys you have to press are all broken). A puzzle involving a child's toy piano with pictures of birds on it appears in ''VideoGame/SilentHillShatteredMemories'', as a ShoutOut to the original game.
* You don't actually have to solve a puzzle, but in ''VideoGame/ChronoTrigger'' playing an organ always reveals hidden doors.

* ''VideoGame/LunarTheSilverStar'' has a duet between true lovers as the key to one dungeon. A long-distance duet between the leads opens it. Kyle and Jessica make for a DreadfulMusician duo, while Nash is too worried about stepping on Mia's notes to harmonize.
* ''VideoGame/IllusionOfGaia'' requires protagonist Will to play specific tunes on his flute to open several gates.
* ''VideoGame/PhantasyStarII'': In order to get the card keys to open the Dams, you need to play a keyboard, however you must learn the Musik skill to even be able to play the keyboard. At one point, you ''trade away'' one of the songs you no longer need.

* Frequently in ''VideoGame/ZorkNemesis'', since the element of water is associated with music and the alchemist of water was a music teacher. The first one is a fountain which can be opened by turning on streams of water which correspond to the notes in a melody played on pan pipes.
* Near the end of ''VideoGame/GodOfWarIII'', there's a puzzle that doesn't even bother trying to hide what it is, as the "notes" are copies of the UsefulNotes/PlayStation's four main buttons and the tune you play is the franchise's {{leitmotif}}.

* In ''VideoGame/TheLostCrown'', Nigel must repair a church organ and then play a specific sequence of notes to banish an evil ghost which blocks his path to a vital clue.

* ''VideoGame/DreamChronicles'' series loves "repeat the sequence" puzzles involving pressing the keys of some musical instrument (even if it's just the key order you have to memorize, not the tune itself - you can see which keys are being activated).
** The original game has the piano room, where clicking portraits on the wall will produce different tunes for you to repeat; completing them all opens the door to the outside.
** The second game has the organ room, where you need to repeat several tunes in order to unlock the passage to the second floor. Another floor has a puzzle requiring you to put several musical instruments in proper order, indicated by a book found in the library.
** The third game has another organ-like instrument, where the same sequence-repeating type of puzzle protects several items you need to obtain.
* The FMV ''Lawnmower Man'' game has a very basic Simon-like musical keyboard level, but it takes forever to watch the player character enter the code after you do.
* In the text adventure ''AugmentedFourth'', the player character has occasion to play a piece called "The Well-Tampered Xylophone", which consists of exercises in "twenty-five keys". The extra one turns into an actual key.
* Most of the time in ''VideoGame/{{Aquaria}}'', Naija uses her songs to [[VoluntaryShapeshifting change into a form]] that is best suited for passing a certain obstacle, i.e. using the Beast Form to swim past strong currents. However, there are a couple of cases where just singing is enough to remove an obstacle, such as the door in the Song Cave, the whale in The Abyss, and [[spoiler: Li's cage near the end of the game]].
* In the ''Bloodmoon'' expansion for ''VideoGame/TheElderScrollsIIIMorrowind'', the Ritual of Earth requires you to listen to a set of geysers from some stalactites and then activate the stalactites in the same order.

* ''Literature/OldKingdom'': A shortcut to Abhorsen's House in ''Sabriel'' will only open to the sound of Mosrael, a bell which is otherwise never used in the series (it sends the ringer into Death).

Subtrope of SolveTheSoupCans. Compare with MusicalTrigger. Can be related to OnlySmartPeopleMayPass, if actual musical ability is required.

SisterTrope to OpenSesame, when the password is a spoken phrase.

** ''VideoGame/TheLegendOfZeldaOcarinaOfTime'': Just as when its predecessors in the franchise often removed something barring your progress (except in ''A Link to the Past''), Link's ocarina can be used for the same purpose. Zelda's Lullaby will trigger mechanisms if Link stands on "the Crest of the Royal Family" aka the Triforce; the Song Of Time removes and summons blocks with the Door Of Time's design on it, starting with the Door Of Time itself; and the Song Of Storms opens up the Bottom Of The Well.

** 2nd Edition AD&D supplement ''The Ruins of Undermountain II: The Deep Levels''. The Undermountain dungeon has a number of {{Cool Gate}}s (magical {{teleportation}} devices) that allow access to it. In the ''Campaign Guide'' booklet, the table of Random Gate Effects includes a gate that is activated by the playing of a specific musical tune.

* ''VideoGame/TheLegendOfZeldaOcarinaOfTime'', taking from a few earlier games, has several dungeons that you unlock by playing different songs on your ocarina.
** Also playing the Song of Time will move some blocks that have the Door of Time's symbol on it.
** They are all a character or area's {{leitmotif}}... For example, the Sun's Song is the ''sun's'' leitmotif; it plays whenever the sun rises [[spoiler:and the sun rises whenever the song is played]].
** And ''VideoGame/TheLegendOfZeldaMajorasMask'', its direct sequel as well.
** And ''[[VideoGame/TheLegendOfZeldaTheWindWaker Wind Waker]]'', where the notes are conducted on the titular baton.
** Averted in the sequel, ''[[VideoGame/TheLegendOfZeldaPhantomHourglass Phantom Hourglass]]'', where there is no instrument whatsoever. The third game, ''[[VideoGame/TheLegendOfZeldaSpiritTracks Spirit Tracks]]'', however, makes up for this with the Spirit Flute, which utilizes the DS microphone. Playing duets with the Lokomos help restore the Spirit Tracks, which enable you to go to new areas.

* In ''VideoGame/ChronoCross'', each element has a unique tone when cast in battle. Playing [[spoiler: the Song of Life]] with these tones when fighting the FinalBoss will instantly win the battle and free [[spoiler: Schala from Lavos]]. This unlocks a better ending than the player would get by killing the boss.
** Being able to pull it off successfully is hard because the boss can interrupt (or help) the melody with his own magic.

* ''VideoGame/PhantasyStarII'': In order to get the card keys to open the Dams, you need to play a keyboard, however you must learn the Musik skill to even be able to play the keyboard.
** At one point, you ''trade away'' one of the songs you no longer need. ...zah?

** ''VideoGame/KingsQuestVIIThePrincelessBride'' has another music puzzle in Etheria involving a harp, which will transport Valanice to a sort of pocket dimension where she can speak with the Three Fates if she plays the right notes on it. The clues to the notes are given by the faerie dragons flitting around in another area of Etheria.

* ''VideoGame/AlidaTheEnigmaticGiant'': Vaults scattered around the island are fitted with sensitive microphones which pick up the sound from the island's massive, fully functional electric guitar. Each and every component of the guitar must be set correctly - and that includes the peghead, switch, and potentiometer dials, before the guitar's sound can open the doors, provided a designated door has been primed to receive the sound, that is.
** The same game also has a small keyboard of tubular bells that unlocks the tram to the Switch.

* In the ''WesternAnimation/SouthPark'' episode "Towelie", Towelie attempts to remember the code to enter the "Secret Government Base". The buttons make a noise as they are pressed and Towelie plays the tune to "Funky Town". Which doesn't open the door.
%%** The episode "Imaginationland" uses this as an OverlyLongGag.

* The earliest hackers (known as Phreakers) would use a tone of 2600 Hz which caused a telephone switch to think the call was over, leaving an open carrier line which could be exploited to provide free long-distance and international calls.
** The tone was discovered in approximately 1957, by Joe Engressia, [[DisabilitySuperpower a blind seven-year old boy. Engressia was skilled with perfect pitch, and discovered that whistling]] the fourth E above middle C (a frequency of 2600 Hz) would work.
** For extra fun, [[FreePrizeAtTheBottom free whistles given out in Cap'n Crunch cereal boxes]] also produced a 2600 Hz tone when blown.
** An electronic gadget for doing this was the first product that Creator/{{Apple}} co-founder Steve Wozniak ever sold.

* ''VideoGame/AlidaTheEnigmaticGiant'' takes this UpToEleven. Vaults scattered around the island are fitted with sensitive microphones which pick up the sound from the island's massive, fully functional electric guitar. Each and every component of the guitar must be set correctly - and that includes the peghead, switch, and potentiometer dials, before the guitar's sound can open the doors, provided a designated door has been primed to receive the sound, that is.

[[quoteright:300:[[ComicBook/DisneyDucksComicUniverse https://static.tvtropes.org/pmwiki/pub/images/bonnie_4.png]]]]

[[quoteright:350:[[ComicBook/DisneyDucksComicUniverse https://static.tvtropes.org/pmwiki/pub/images/bonnie_4.png]]]]

[[quoteright:300:[[Series/DoctorWho https://static.tvtropes.org/pmwiki/pub/images/musical_key05x.png]]]]
[[caption-width-right:300:[[Recap/DoctorWho20thASTheFiveDoctors Hanging a painting]] of how to unlock your [[BookcasePassage hidden door]] on [[HiddenInPlainSight the door itself]] is the Time Lord equivalent of [[ThePasswordIsAlwaysSwordfish setting your password to "password"]].]]

** ''Myst IV'' involves using Sirrus' Spider Throne to vibrate four different pieces of minerals, so that all of them being pushed out of their literal "locks" deploys a bridge [[spoiler: to a bomb factory.]] The musical element comes from the tones Spire's crystals give off when their electrical charge fades, which the Throne channels via huge cables within the Age.

!!Examples:

* ''TabletopGame/DungeonsAndDragons''.

* At one point in ''VideoGame/TheNeverhood'', you have to open a door by spitting into a SeriesOfTubes to make them whistle the same tune as another series of tubes.

Using music and musical instruments as security measures. Pianos or similar instruments are common, as you are dealing with keys. Can often be the way to conceal your secret lair by being HiddenInPlainSight. The tune itself may be significant/ironic, or the [[ThemeTuneCameo Theme Tune]] or {{Leitmotif}} of a character.

* In ''Anime/MaiOtome'', a specific song, from which each of the three main characters knows one verse each, is one of the three requirements for activating [[spoiler:the Harmonium]].

* Near the end of ''VideoGame/GodOfWarIII'', there's a puzzle that doesn't even bother trying to hide what it is, as the "notes" are copies of the PlayStation's four main buttons and the tune you play is the franchise's {{leitmotif}}.

* In a ''[[ComicBook/DisneyDucksComicUniverse Scrooge McDuck]]'' story by Carl Barks that's a riff on ''The Hunchback of Notre Dame,'' Scrooge programs his vault so that it can only be opened by playing "My Bonnie Lies over the Ocean". Trying to protect his secret by using a wishing well (ItMakesSenseInContext), he inadvertently reveals it to the hunchback (who lives near the bottom of the well scooping up the coins people throw in and eavesdropping on their wishes in the process), which kicks off the plot.
** A ''Ducktales'' comic written for ''Disney Adventures'' had a similar plot, in which Scrooge has a voice-activated lock to the vault on his money bin which only opens when it hears him singing the opening lines of "Comin' Through the Rye". And the Beagle Boys just so happen to have a cousin, Baritone Beagle, who's good at impressions...
* In one issue of ''Comicbook/MuppetBabies'', the group imagines that the world is running out of music. In their imaginations, it turns out that it's being eaten by the Note-All, with approval from Piggy, who wants ''her'' music to be all there is. His ''staff'' puts the ''rest'' behind ''bars''. When the Note-All eats Piggy's singing, as well, she decides to go free her friends. When physical keys don't unlock the bars, Rowlf suggests a ''musical'' key. When Piggy hits high C, the bars open.

** Another puzzle, this one courtesy of the Riddler, featured a door and three keys, labelled "A", "C" and "D". Batman tries the "D" key, which releases two saw blades that he and Robin dodge. He's about to try the "A", when Robin stops him saying that will release three blades. This is because they are musical keys and the key of C? No sharps.