bother, maneuver, follow, trail, stalk, hound, watch, shadow, exploit, impose, interrupt, harass, encroach, expose oneself, spy on, walk up to, insinuate oneself into, worm one's way into, intrude on, insert oneself, muscle in on, meddle in, foist oneself on, introduce oneself into, track down, creep up on, go after, impinge on, position oneself, horn in on, poke one's nose into, vie (for attention)
drill, belt, clap, trill, hum, sing, chant, warble, hear, accent, anticipate, fade, pick out, improvise, breathe, sustain, harmonize, inhale, ring out, enunciate, lull, lullaby, resonate, reverberate, beatbox, break out (in harmony), come in (on the bridge), sweeten (the tone), darken (the tone), scat, vamp, riff, build (a repertoire), drag the beat, swing (the rhythm), rehearse (a passage), practice (scales), warm up (one's voice), support (one's voice), phrase (a musical line), interpret (a song), sing out, croon, interpret (the lyric), articulate, memorize (lyrics), sight-read, count out (rhythm), beat out (rhythm with one's foot), read (a score), listen (to one's voice in the monitor), brush up (one's technique), practice (musical scales), grip (the mic), pan (the mic), relax (one's mandible), correct (the pitch), warm (the quality of sound), slide (a note), perform (a song)