(n.) An improviser, or improvvisatore.

Heldentenor Meistersinger accompaniment aria singer baritenor baritone bass basso basso buffo basso cantante basso continuo basso ostinato basso profundo bassus blues singer canary cantatrice canto cantor cantus cantus figuratus cantus planus caroler chanter chantress coloratura soprano comic bass continuo contralto countertenor crooner deep bass descant diva dramatic soprano drone falsetto figured bass ground bass head register head tone head voice heroic tenor hymner improvisator lead singer lieder singer line male alto melodist mezzo-soprano opera singer part plain chant plain song prick song prima donna psalm singer rock-and-roll singer singer singstress songbird songster songstress soprano tenor thorough bass torch singer treble undersong vocalist vocalizer voice voice part warbler yodeler