An instrumental is, in contrast to a song, a musical composition or recording without lyrics or any other sort of vocal music; all of the music is produced by musical instruments. Specifically, this term is used when referring to popular music; some musical genres make little use of the human voice, such as jazz, electronic music, and large amounts of European classical music (although in electronic music the voice can be sampled just like anything else). In commercial music, some tracks or songs on a compact disc include instrumental tracks. These tracks are exact copies of the corresponding song, but do not have vocals.