essential or central; of great importance or relevance. / Serving as an instrument, medium, means, or agency.

(grammar) The instrumental case. / (music) A composition written or performed without lyrics, sometimes using a lead instrument to replace vocals.

(rare) Usefulness or agency, as means to an end; instrumentality / (music) How likely the music contains no spoken word vocals

By means of an instrument or agency; as means to an end / With instruments of music

(uncountable) The quality or condition of being instrumental; serving a purpose, being useful. / (countable, law) A governmental organ with a specific purpose.

(philosophy) In the philosophy of science, the view that concepts and theories are merely useful instruments whose worth is measured not by whether the concepts and theories are true or false (or correctly depict reality), but how effective they are in explaining and predicting phenomena.

plural of instrumental

(music) The backing track of a song. The audio of a song without the vocal track.

(transitive) To make into an instrument for achieving a goal. / (music, transitive) To transcribe for instrumental execution a piece of music written for the human voice

present participle of instrumentalize