What meditation music is for, and what it must not do
Meditation music has one job: to hold attention gently without ever grabbing it. That rules out most of what makes other music interesting. No drums or a very soft pulse, no melodies that resolve into a hook, no dynamic swells, no sudden entries. What remains is texture: long pad notes that shift slowly, a low drone, a singing bowl struck every few bars, soft flute or a single piano note left to ring, and the room itself, rain, a stream, wind through trees.
Tempo barely applies. Many pieces are effectively beatless; when a pulse exists it is slow, around 50 to 60 BPM, close to a resting heart rate. Say beatless or no drums, spacious, slow and evolving in your prompt and the generator keeps its hands off the energy. Keep the description short; a long list of instruments produces a busy mix, and busy is the one thing this music cannot be.