verb

lose strength or momentum.

the music faltered, stopped, and started up again

hesitate,delay,drag one’s feet,stall,think twice,get cold feet,change one’s mind,waver,oscillate,fluctuate,vacillate,be undecided,be indecisive,be irresolute,see-saw,yo-yo,haver,hum and haw,sit on the fence,dilly-dally,shilly-shally,pussyfoot around,blow hot and cold,tergiversate