Percussion Instrument of Wooden Keys and Mallets

Puzzle 11 of School Dance Pack

Question is: Percussion Instrument of Wooden Keys and Mallets

and the answer is: XYLOPHONE

Word Meaning:

XYLOPHONE — (music) Any musical instrument (percussion idiophone) made of wooden slats graduated so as to make the sounds of the scale when struck with a small drumstick-like mallet; the standard Western concert xylophone or one of its derivatives.

Definitions from Wiktionary.