In turn, royalties from the playing of each track on the "album" were to be used to crowdfund a free concert tour by the band.

In August, Vulfpeck announced the admission-free Sleepify Tour in the United States scheduled for September 2014.

[6] Tim Jonze of The Guardian facetiously reviewed Sleepify, stating that the "opening track 'Z' certainly sets the tone, a subtle, intriguing work that teases the listener as to what may come next.

It's followed by 'Zz' and 'Zzz' which continue along similar lyrical themes while staying true to Sleepify's overriding minimalist aesthetic.

"[4] While a Spotify spokesperson had previously considered the stunt to be "clever" (joking that the album was "derivative of John Cage's work," a reference to the silent piece 4′33″),[4] Sleepify was pulled from the service in late-April 2014, citing an unspecified violation of the service's content policies.

[7][8][9][10] The album's royalty-generating scheme received worldwide press coverage, including Spiegel of Germany, Editora Abril of Brazil, The New Zealand Herald, El País of Spain, Komsomolskaya Pravda of Russia, and Time magazine of the U.S.[11] Rolling Stone noted that Spotify still streams the Cage composition 4′33″—a performance piece in which musicians refrain from playing their instruments.

[10] A similar concept emerged in June 2015 via a website known as Eternify, by the band Ohm & Sport, which allowed users to play the first 30 seconds of any Spotify song on a loop, thus accumulating royalty payments for the artist.