[[quoteright:320:https://static.tvtropes.org/pmwiki/pub/images/sleepy_1642.jpg]]
[[caption-width-right:320:[-''[[https://www.youtube.com/watch?v=vYC3VBvhAao&hd=1 Este recuerdo guarda su alma / Su alma guarda esta tumba. / ¡Dios guarda su cuerpo / Su cuerpo guarda su aliento! / Behold the breath of the Dragon / ¡Mira el brillo del cuchillo!]]''-] ]]

Sleepytime Gorilla Museum (often abbreviated to SGM) was an American experimental rock band, formed in 1999 in Oakland, California. The band fused contemporary classical, industrial, and art rock characteristics into a very idiosyncratic melange. Though thoroughly outside the mainstream of popular rock music, the band received high critical acclaim for their ability to combine diverse musical elements in nuanced and complex ways, often incorporating advanced theoretical considerations, while avoiding either ostentatious 'artiness' or ironic [[{{Postmodernism}} po-mo pastiche]] and remaining eminently [[RuleOfFun listenable for mere enjoyment]].

The band was begun by ''Nils Frykdahl'' (guitars, flutes, bells, others) and ''Dan Rathbun'' (bass, 'log' dulcimer, trombone, lute, others) of the band Idiot Flesh with ''Carla Kihlstedt'' (violins, percussion guitar, autoharp, organ, bulbul, others) of the band Charming Hostess, and included at various times:
* ''Michael Mellender''
* ''David Shamrock''
* ''Matthias Bossi''
* ''Frank Grau''
* ''Moe! Staiano''
All had comprehensive musical training, all sang for the band, and played a variety of odd custom instruments designed by Rathbun for unique sonic properties.

Known for bringing a sense of performance art to their live act, the band (dressed in homemade costumes and makeup) would engage in elaborate stage shows including [[ItRunsOnNonsensoleum pseudoscientific demonstrations]], the telling of apocryphal stories about [[UsefulNotes/{{Dada}} dadaists]], and packing up and leaving the stage before returning to continue playing, often inviting the audience to participate in various ways.

Lyrically they were very kitchen sink, as befitting a group lacking one predominant songwriter, though an overall thematic of [[{{Absurdism}} absurdity and concomitant humour]] permeates most of the band's work. A strong literary and artistic sensibility informed the band's dispensations on topics such as subjectivity, (anti)humanism, and (anti)realism, though you'll [[GeniusBonus never hear those words uttered]] [[{{Symbolism}} in the songs themselves]]; and their frequent [[ShownTheirWork quotations from, citations of, and allusions to]] various figures and sources, from ''James Joyce'', to ''G.W.F. Hegel'', to ''Louise Bourgeois'', and ''the Unabomber'', combined with the occasional BilingualBonus, reward careful and detail-oriented appreciation without [[ViewersAreGeniuses demanding it up front as the price of admission]].

!! Albums:
* ''Grand Opening and Closing!'' (2001)
* ''Of Natural History'' (2004)
* ''In Glorious Times'' (2007)
* ''of the Last Human Being'' (2024)
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!!This band exhibits the following tropes:

* BizarreInstrument: Too many to include, but to name one — the 'sledgehammer dulcimer', a long wooden tube strung with 7' grand piano strings, played with a hammer and a metal cylinder (which acts as a sliding fret, making this instrument microtonal).
* Literature/DoNotGoGentleIntoThatGoodNight: They quote the poem in ''Sleep is Wrong''.
* EldritchAbomination: ''The Donkey-Headed Adversary of Humanity'' is a character in the band's first two albums and something of an overall mascot as well.
* EverybodyHatesMathematics: {{Subverted}}, since a number of their songs include mathematical themes, and the band were fond of stories about dada artists and mathematicians (both real and fictitious).
* EverythingIsAnInstrument: Dan Rathbun provided most of the custom-made instruments played by the band members. Some of them are made of kitchen tools, rare metal objects, and even parts from other instruments.
* FadingIntoTheNextSong:
** ''Of Natural History'' uses it extensively.
* HarshVocals: Nils Frykdahl serves as the prime example, but the rest of the band members have proven to be successful in using this technique proficiently from time to time.
* IndecipherableLyrics: See the "''Word Salad Lyrics''" example below.
* MadMathematician: Several of them are quoted in song lyrics as sources to their fictitious stories. An example can be found on ''FC: The Freedom Club'', which quotes and refers to American mathematician and anarcho-primitivist [[http://en.wikipedia.org/wiki/Theodore_Kaczynski Ted Kaczynski]].
* MadOracle: The story told in their first two albums features a HumanoidAbomination known as ''The Donkey-Headed Adversary of Humanity'', who prophesies an unimaginable catastrophe awaiting humanity.
* MotorMouth: Nils especially, though all of them pitch in.
* RockMeAsmodeus: "A Hymn To The Morning Star"
* RomanticismVersusEnlightenment: Their second full-length release, ''Of Natural History'', is a concept album exploring this theme. Arguably the band's [[AccentuateTheNegative darkest]] work, its various tracks include mocking paeans against Christianity (''A Hymn to the Morning Star''), songs which threaten humanity with annihilatory violence (''The Donkey-Headed Adversary of Humanity Opens the Discussion'', ''Bring Back The Apocalypse''), venomous lyricisations of murderous technophobic terrorism (''FC: The Freedom Club''), and songs about the alienating effects of a consummate technorationalistic enlightenment culture (''Phthisis'', ''The Creature'', ''Babydoctor''). Despite all that, the album as a whole doesn't particularly come down on the {{Romanticism}} side so much as it comes down hard and heavy on the [[SlidingScaleOfidealismVersusCynicism Cynicism]] side.
** All of this, by the way, is punctuated and bookended by field recordings of [[SwampsAreEvil bog sounds]], [[DontGoIntoTheWoods animal growling and snarling]], bird calls, the swarming of insects, and recorded conversations with ''[[DeepSouth colorful]]'' [[DeepSouth rural folks]].
* SensoryAbuse: While little of it could ever be mistaken for mellow easy listening, some songs in particular prominently feature freakish dissonances, abrupt screaming, bizarre grinding, scraping, popping, or clicking, shrill screeching, or any combination of these with sudden dynamic explosions of volume. Songs like ''The Stain'' and ''Ossuary'' come to mind.
* UncommonTime: A staple of their experimental rock/metal style. The work on their first album was said by the Pitchfork to resemble a mixture of Music/LascaillesShroud, Music/{{Meshuggah}} and Secret Chiefs 3.
* WordSaladLyrics: The lyrics of ''Helpless Corpses Enactment'' are a series of direct quotations from ''James Joyce'''s infamous novel ''Literature/FinnegansWake'', known for its radical linguistic experimentation and total abandonment of the conventions of plot and character construction. A selection quoted within the song, for example:
--> ''Vah! Suvarn Sur! Scatter brand to the reneweller of the sky,''
--> ''thou who agnitest! Dah! Arcthuris comeing! Be! Verb umprin-''
--> ''cipiant through the trancitive spaces! Kilt by kelt shell kithagain''
--> ''with kinagain. We elect for thee, Tirtangel. Svadesia salve! We''
--> ''Durbalanars, theeadjure. A way, the Margan, from our astamite,''
--> ''through dimdom done till light kindling light has led we hopas''
--> ''but hunt me the journeyon, iteritinerant, the kal his course,''
--> ''amid the semitary of Somnionia.''

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