composition (often improvised) for a solo instrument (especially solo organ) and not a regular part of a religious service or musical performance
of your own free will or design; not forced or compelled; "man is a voluntary agent"; "participation was voluntary"; "voluntary manslaughter"; "voluntary generosity in times of disaster"; "voluntary social workers"; "a voluntary confession"
controlled by individual volition; "voluntary motions"; "voluntary muscles"
something that serves as a preceding event or introduces what follows; "training is a necessary preliminary to employment"; "drinks were the overture to dinner"
a minor match preceding the main event
designed to orient or acquaint with a situation before proceeding; "a preliminary investigation"