Animator David Firth's Incredible Mouth Band video depicts a group of musicians who instead of playing their instruments create a song by saying the names of the instruments.
Link
UPDATE: BB reader Robert T says:
(The Incredible Mouth Band) reminded me of a song done by The Who, back in 1966, called "A Quick One While He's Away." The band wanted to put string parts on the song, but the band's manager said that they couldn't afford the costs ( which is not surprising as the band was many tens of thousands of pounds in debt at this time ). So, as a joke, they sang the word "Cello" repeatedly where they thought the cellos would play in the song. Link