Answer: mistune

AnswerCrossword Clue
MISTUNEMake a B instead of an A?
mistuneto adjust (a radio or television) to receive a broadcast
mistuneto adjust (a musical instrument) to the correct pitch
mistunethe state of proper pitch, frequency, or condition
mistuneto tune incorrectly
mistuneagreement
mistunemelody
mistuneto adjust (a motor) to run smoothly