Definition of demonstration record in US English:

demonstration record

noun

  • 1A gramophone record used to demonstrate the capabilities of a piece of hi-fi equipment, or of the type of record itself (now rare).

  • 2A recording made to demonstrate or display the abilities of a singer, musician, or group, or to promote a new song, style of music, etc., especially to record companies, disc jockeys, and agents.

Origin

Early 20th century; earliest use found in The Washington Post.