ETYM Latin voluntarius, from voluntas will, choice, from the root of velle to will, p. pr. volens; akin to Eng. will: cf. French volontaire, Of. also voluntaire. Related to Will, Benevolent, Volition, Volunteer.
1. Of one's own free will or design; not forced or compelled.
2. (Physiology) Controlled by individual volition.

ETYM See Voluntary (adj .).
Composition (often improvised) for a solo instrument (especially solo organ) and not a regular part of a service or performance.
Music, (improvised) music introducing or closing performance or church service.
In music, a generic term for a quasi-improvisatory composition of the 16th century, but more specifically a piece for solo organ played at the beginning or end of a church service. As the name suggests, the organ voluntary is often free in style, and may be improvised. During the 16th century voluntaries were usually short contrapuntal pieces, without a cantus firmus (“fixed melody”). In the 17th and 18th centuries they developed a more secular style, incorporating elements of the suite, sonata, toccata, and even the operatic aria. Composers of voluntaries include Purcell, John Blow, and Samuel Wesley.