THESAURUS
humming
bel canto, birring, bombilation, bombinating, bombination, booming, bravura, burring, busy, buzzing, choral singing, coloratura, croon, crooning, droning, folk singing, fussy, hopping, hum, hustling, intonation, lively, low rumbling, lyricism, operatic singing, popping, purring, scat, scat singing, singing, sol-fa, sol-fa exercise, solfeggio, solmization, song, thrumming, tonic sol-fa, vocal music, vocalization, warbling, whirring, whizzing, yodel, yodeling