Part of a piano (3)
'part of a piano' is the definition.
(I know that key is part of keyboard)
This is all the clue.
(Other definitions for key that I've seen before include "Piano lever" , "Device for lock" , "It opens the door" , "Small island" , "Scale system for music" .)
(Other definitions for pedal that I've seen before include "ride a cycle" , "Power a bike" , "Foot-operated control" , "Part of cycle" , "Of or relating to the feet" .)