According to Osho, music can certainly be set to OM, but any effect you feel is from the harmony and rhythmic consonance of notes—not from the syllable itself. What matters is rhythmicity’s impact on the psyche, which can create only an apparent peace. Mechanical OM-chanting dulls awareness, breeds tamas (inertia), and leads to mediocrity; real spirituality demands alertness, not hypnotic repetition.
You can make music with OM, but any calm you feel is from the tune and rhythm, and repeating OM like a machine just lulls your mind instead of waking it up.