This paper describes the intensive psychotherapy of a late-adopted boy who had been severely traumatised in his first five years of life. In describing the progress and then deterioration of his mental state and his psychotherapy, I examine the development of his compassion for the vulnerable side of himself, as part of a battle between identification with the vulnerable and sadistic aspects of his internal world. I trace how this compassion was reflected in his concern for others in his external world and fantasised others in his play. I also describe the use of sound and rhythm in enabling him to experience sufficient containment in his psychotherapy for his deepest preoccupations to begin to emerge. In so doing, I examine literature on music and musicality, and seek to demonstrate the relevance of Suzanne Maiello’s advocacy of listening with a ‘musical ear’ to psychotherapy with looked-after and traumatised children, whose life ‘rhythms’ have been so catastrophically disrupted.