I haven’t heard of the term FMA. I do know that music therapy was very beneficial for my son. (It was very disappointing when we lost our MT due to her changing jobs due to the pandemic). He really enjoyed it & kids also get the benefits of doing some fine motor work with using the various instruments. It definitely encourages communication & is highly motivating for kids who love music. If the music therapist has an MBT degree, this assures that she is a legitimate provider. I highly recommend trying it for your son.👍