Answer: modulate

AnswerCrossword Clue
MODULATE

Soften

MODULATE

Tone down

MODULATE

Shift from one key to another, in music.

MODULATE
Soften.
MODULATE
Tune to a key or pitch
MODULATETune to a pitch
MODULATEAdjust, as pitch
MODULATEVary, as a tone
MODULATEAdjust, as a voice