from what i am aware of. some forms of music can be played to soothe people with AS.
it is risky therapy as what soothes some will enrage other....just try putting on heavy metal thrash, i go completely nuts.
i do like and will play oiver and over addagio for strings.
i am not sure if it is a specific and recognised therapy, but the cottage industry surrounding AS will get you in a room, ask what your favourite music is, play it to you and charge you £50.