“Why do people make music?”

Not so minor detail:
The Lord, in the Lord's infinite wisdom, did not give “people” a natural ability to "make" music. The vast majority never attempt to learn an instrument, even fewer how read musical notation; professional composers, arrangers & conductors are rarer still. Pitch, resonance, rhythm, tone, volume and other minor considerations aside, +99.9% of all God's chilluns can sing.

PS: If the Shaman said rocks and rivers have "spirits," that will be the correct answer on the Shamanism pop quiz, 40K years ago or today, bone flute or brass. Believe it or don't.