warble — to sing or whistle with trills, quavers, or melodic embellishments: The canary warbled most of the day.
noun caroled
chorused — Music. a group of persons singing in unison. (in an opera, oratorio, etc.) such a group singing choral parts in connection with soloists or individual singers. a piece of music for singing in unison. a part of a song that recurs at intervals, usually following each verse; refrain.
strained — affected or produced by effort; not natural or spontaneous; forced: strained hospitality.
