Answer:

airguitar

AnswerCrossword Clue
AIRGUITARRock fan's "instrument"
AIRGUITARInstrument that's not seen and not heard
AIRGUITARInstrument "played" for a hairbrush microphone user
AIRGUITARImaginary instrument
AIRGUITARPretend-player's "instrument"
AIRGUITARPart of some pretend performances
AIRGUITARIt's not seen in musical performances
AIRGUITARWannabe rocker's instrument
AIRGUITARYou may pretend to pick one