Alternative Rock used to be a less known alternative for the more mainstream sounds at the time of their origin. Nowadays it doesn't make as much sense due to popularity. In fact, it's rare to find a modern rock band without "alternative rock" or "indie rock" on their Wikipedia page.
Pop: These days if a ballad is released without any rock overtones, it's pop music, regardless of whether it is Popular or not.
Indie: Even when the band is on a major label, their genre is still short for 'independent'. (However, "indie rock" can also be used to denote a genre, specifically a lo-fi and mellow strain of rock music.)
Emo. Originally used to refer to a less violent and confrontational, more personal type of hardcore punk that was emerging in Washington, D.C. in the 80s, the term is derived from "emocore", which itself was short for "emotional hardcore". Today, "emo" is used to describe a type of music that is barely distinguishable from pop-punk, and the fashion style and the association with any mental state other than "constantly happy". It is notable that some modern-day fans who don't know the history of the genre mistakenly believe it's short for simply "emotional".
New Age Music is more of a marketing term. Very few artists labelled as "New Age" actually have any connection to "New Age" religions. Some of them even reject the label and propose replacements like "Folk Ambient" or "Instrumental Chillout".
'Los cuatro cuartos' (The four quarters) are 5 members.
'Banana 5' are 6 members
An interesting example comes in the form of punk band Dillinger Four. Their name was originally The Young Dillingers after a name they saw in a record sleeve under the Thank You list. When it turned out to be the name of a local gang they changed it Dillinger Four. At the time of naming, they only had three members so it was just a silly joke. Then they added a second guitarist and the joke just sort of became a normal name.
"Unchained Melody" was named after the movie it originally appeared in, Unchained. The movie is largely forgotten, but thanks to covers and use in other movies (most notably Ghost), the melody is still popular.
The "classic" Emonote Which is actually a style of post-hardcore music that bears virtually nothing in common with the mainstream label, see the entry above band Sleepytime Trio started out as a trio, but added a fourth member not too long after formation, and were a four-piece for almost their entire existence, yet they kept the name anyway.
This might be the best way to explain the stage name of singer P!nk. When she first started, she actually had pink hair◊. However, as time has gone by, she has changed it to blonde. Although, she says her stage name came from Mr. Pink in Reservoir Dogs, so it's possible that the hair was only dyed pink to explain the name, instead of the name coming from her hair.
For that matter, the same thing happened to Power Metal (the original name for speed metal, now the name for fantasy metal) and Thrash Metal (which used to mean progressive speed metal with clean vocals whereas the modern equivalent is closer to 80s death metal).
Occasionally, a musician from a band that has broken up will join a new band, and that band will use the old band's name to take advantage of the name recognition and/or record contract. Happened notably with Scorpions in the early 1970s.
Pop insert-genre-here ends up sounding more pop than that genre. Fast.
Much mainstream "Country Music" is contemporary pop or rock with a steel guitar and a singer with a twang. There's still a few successful artists that adhere to a more traditional sound, though.
OMGG, a bluegrass band particularly notable for the fact that its bandmembers have all been playing since they were quite young - the name stands for "Obviously Minor Guys and a Girl". The oldest already isn't particularly "obviously" minor, and soon enough none of them will be.
Few music "albums" have actually been a book of discs in sleeves ever since the LP format made it convenient to put ~50 minutes of music on just one. And that was several decades ago.
Similarly, many box sets come in hardback book form with CD holders, rather than in a box.
The terms single, EP, and LP originally denoted different formats of vinyl records, but are still used today in describing the length of a recording despite most music coming out on the same format (usually CD or MP3 download) regardless of length.
In Germany, the term 'maxi CD' is often used to refer to a CD single. It was originally designed to refer to CD singles which had more than two tracks, but came to refer to all of them.
Country music duo Baillie & the Boys had only one "boy" in it for several years following the departure of Alan LeBoeuf in 1988, leaving it as a husband-and-wife duo of Kathie Baillie and Michael Bonagura. They later signed on Roger McVay as an unofficial third member, but LeBoeuf returned in 1998.
Subverted by the Thompson Twins. A trio at the height of their popularity (they had anywhere from four to six members in their early years), they became a duo after bassist Joe Leeway left.
Japanese Power Metal band Versailles found out when they tried to perform in the US that there was already an American band named Versailles and changed their name to Versailles Philharmonic Quintet—a name which became awkwardly inappropriate after bassist Jasmine You's sudden death in 2009. While promoting their second album, they continued to use◊ the Versailles Philharmonic Quintet name despite only having four members. (The name became accurate again when support bassist Masashi joined the band proper in late 2010.)
The "TVT" in now-defunct record label TVT Records technically stands for "TeeVee Toons": The label's first release was Television's Greatest Hits, a compilation of TV theme songs. Though TVT kept releasing the occasional collection of tv themes or commercial jingles throughout it's run, it became better known for music well outside that niche, signing successful acts such as Nine Inch Nails and Lil Jon.
GRIMMS were a pop/comedy band formed in 1971 by members of the Scaffold, the Bonzo Dog Doo Dah Band, and the Liverpool Scene; the band's name was formed from the initials of original core band members John Gorman, Andy Roberts, Neil Innes, Mike McGear, Roger McGough, and Vivian Stanshall. However, Stanshall left the band in 1972 and McGear followed a year later, so that only four of the members referred to in the band name were left in the band by their breakup in 1976; moreover, after their first two performances, the band expanded to include many additional members not referenced in their name.note Nine, to be exact, though not all at once. Adrian Henri, Brian Patten, Michael Giles, John Megginson, and George Money contributed to the first album, Grimms; Henri, Giles, and Money left in 1973 and were replaced by David Richards, Peter Halsall, and Gerry Conway for the second album, Rockin' Duck, while Patten left in 1974 and Halsall and Conway left in 1975 to be replaced by Timmy Donnell for the third album, Sleepers.
The Air from J.S. Bach's Orchestral Suite No.3 in D major is commonly known as "Air on the G-String" after a once-popular arrangement created by 19th-century violinist August Wilhelmj, even though it is now more usually played in its original arrangement.note As the melody only covers a range of a minor tenth (A4-C6), it can be played quite easily on a single string; the original version can theoretically be performed entirely on the A string, but Wilhelmj transposed the piece down by a major ninth so that it could be played on the G string.
Pretty much any band of youngsters identified as "boys", "girls" (maybe less so) or "kids" (i.e. Backstreet Boys, The Beach Boys, New Kids on the Block) where the members have grown up automatically becomes this. It happened to Sonic Youth long before their hiatus and will apply to Youth Group (whose biggest hit to date is a cover of Alphaville's "Forever Young") if they ever emerge from their own hiatus.
Snoop Dogg's stage name derives from Snoopy, a cartoon dog. When he changed his name to Snoop Lion, the "Snoop" part became an artifact.
The SilverchairB-Side "Punk Song #2". They originally used "Punk Song #1" and "Punk Song #3" as titles for other songs written around the same time, but only "Punk Song #2" ended up keeping its Working Title: "Punk Song #1" became "Lie To Me" and "Punk Song #3" became "Satin Sheets".
The Mandarins were founded in 1963 as an all-Asian drum and bugle corps. Today, corps membership comes from all ethnic groups.
Duran Duran's 1983 followup to their breakthrough smash album Rio was called Seven and the Ragged Tiger, after a storyline that Simon LeBon had originally envisioned going through all the songs about a group of rebels challenging a repressive state. During the album's difficult production history, that idea was dropped in favor of just getting the record finished on time. Other than the title, it survives only in the concept for the "New Moon on Monday" video (more evident in the longer version).
Walter Becker's 11 Tracks Of Whack album actually has 12 tracks, but Little Kawai was added at the last minute after the title had been decided. In Japan, the album features an additional track Medical Science, giving 13 tracks, yet keeps the original title.
Hamilton, Joe Frank & Reynolds was a soft rock trio composed of Dan Hamilton, Joe Frank Carollo, and Tommy Reynolds. The group continued to use its original name even after Reynolds was replacd by Alan Dennison.
Fifty-something soft-rock duo George Merrill and Shannon Rubicam are still mostly known as Boy Meets Girl.
George Strait's 50 Number Ones contained all 50 of his #1 hits to date, plus the new song "I Hate Everything" as a 51st track. Said song was released as a single... and it went to #1 as well, thus invalidating the album's title in mere months!
Blondie was so named because there were two other blonde singers present for their early rehearsals, both of whom left before they ever played live or recorded anything.