demo

A demo (shortened from "demonstration") is a song or group of songs recorded for limited circulation or reference use rather than for general public release. A demo is a way for a musician to approximate their ideas in a fixed format, such as cassette tape, compact disc, or digital audio files, and to thereby pass along those ideas to record labels, producers, or other artists.
Musicians often use demos as quick sketches to share with bandmates or arrangers, or simply for personal reference during the songwriting process; in other cases, a songwriter might make a demo to send to artists in hopes of having the song professionally recorded, or a publisher may need a simple recording for publishing or copyright purposes.

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