Hum before you play
For some people with aphantasia, sound is an open channel. This tests whether it is for you.
Try exercise ›Music Creative Exercises for Aphantasia
Non-visual music exercises designed to build structural, tactile, and rhythmic prompts without mental imagery.
Answer the loop
Respond to something real instead of generating from nothing.
Try exercise ›Rebuild by ear
Learning something real by ear and then changing it gives you material to push against.
Try exercise ›