音乐
yīn yuè · HSK 2
music
🎵 音 (sound) + 乐 (joy/pleasure) = sound that brings joy
音乐 decomposes as 音 yīn 'sound' + 乐 yuè 'joyful'. The character 乐 reads yuè when it means music but lè when it means happy — same root idea: sound made for pleasure.
乐 — stylized depiction of a wooden instrument with strings
Originally a pictograph of a wooden frame holding strings or bells, representing a musical instrument. The character first meant 'music' (read yuè), and by extension came to mean 'joy, happiness' (read lè), since music brings pleasure. The simplified form 乐 streamlines the older 樂.