instrumental

adj. helpful, useful, serving to assist; of or pertaining to an instrument; written for or played by musical instruments; of a case which expresses means or agency (Grammar)

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.
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Adjective
1. relating to or designed for or performed on musical instruments; "instrumental compositions"; "an instrumental ensemble"
(antonym) vocal
(pertainym) musical instrument, instrument
2. serving or acting as a means or aid; "instrumental in solving the crime"
(synonym) implemental
(similar) helpful

adj. instrumental, of or pertaining to an instrument; helpful, useful, serving to assist; written for or played by musical instruments

adj. instrumental, instrumental case