First and foremost, your son should have a thorough ear and eye test just to make sure everything is ok in that area. You may also consider an assessment by a child psychologist/occupational therapist to confirm if there are any issues with your son, be it attention/behavioural/sensory/other learning difficulties etc.
My son is currently undergoing occupational therapy for attention/sensory issues and this includes the therapeutic listening program. It is not cheap so you need to consider the financial aspect. You need to use special headphones which I think cost about $1500 and then each CD is $400-$500 each. The CD's are specially modified music (some nursery rhymes and classical style music where the beats/tempos have been slightly altered).
It is recommended that the child listen to the music twice a day for min 20mins each day (ideally 30mins), and there should be a 3 hour gap between each session. Each CD should be listened to for 3 weeks before progressing to the next CD. In all, I think there are about 12 CDs. However, you do not need to complete the whole program to see results. I'm told many parents stop once they see positive changes in the child's behaviour.
We were quite skeptical at first, but wanted to try anything to help our son. In our case, the change in my son has been quite remarkable. Before, he used to wander/float around in the classroom and couldn't stay focused to finish a task. We saw improvements very quickly within just a couple of months, and now he's a totally different boy.
I'm not sure if it's just the music alone or a combination of that plus his other occupational therapy which has helped him, but we are glad we gave it a chance.
Pls feel free to PM if you have any further questions.