The goal of this clinical trial is to evaluate the effectiveness of individual sessions of improvisational music therapy for autistic children aged 7 - 11. Researchers will compare the impact of adding improvisational music therapy to usual care alone for autistic children over a 12-week period. Participants will be randomly assigned to one of the following two conditions: the Improvisational Music Therapy (intervention) Group or the support as usual (control) Group. The aim is to achieve seven overarching objectives: 1. To determine whether 12 weeks of individual sessions of improvisational music therapy in addition to support as usual is superior to support as usual alone in improving social communication in autistic children. 2. To examine whether 12 weeks of individual sessions of improvisational music therapy in addition to support as usual is superior to support as usual alone in improving communication skills in autistic children. 3. To examine whether 12 weeks of individual sessions of improvisational music therapy in addition to support as usual is superior to support as usual alone in reducing psychosocial problems in autistic children. 4. To examine whether 12 weeks of individual sessions of improvisational music therapy in addition to support as usual is superior to support as usual alone in improving wellbeing of autistic children. 5. To examine whether 12 weeks of individual sessions of improvisational music therapy in addition to support as usual is superior to support as usual alone in improving adaptive functioning in autistic children. 6. To examine whether 12 weeks of individual sessions of improvisational music therapy in addition to support as usual is superior to support as usual alone in improving anxiety in autistic children. 7. To examine whether the therapeutic relationship predicts the development of social, communication and language skills among autistic children.