abstract: ABSTRACT Two qualitative studies described the effects of parent's participation in the music therapy session on parent-child interaction during home-based musical experiences learned in music therapy session. Home-based musical play was based on two current programs: Sing & Grow (Abad & Williams, 2007; Nicolson, 2008 Abad, 2011; Williams, et al; 2012) and Musical Connection Programme(Warren & Nugent, 2010). The researcher utilized the core elements of these programs, such as session structures and parenting strategies for improving parent-child interaction during music therapy interventions. Several questions emerged as a result of these case studies as follows 1) does parent's participation affect parent-child interaction during music therapy interventions 2) does musical parenting strategies promote parent-child interaction while practicing musical play at home 3) does parent's interaction increase when they practice parental strategies listed on parent's self-check list. Music therapy session was provided once per week during an eight week period. The participants were referred by Arizona State University (ASU) music therapy clinic. Sessions took place either in the ASU music therapy treatment room or the participant's home. There were four participants- one diagnosed with Down syndrome and the other with Autism Spectrum Disorder (ASD) and two parents or caregivers (each subject was counted as one participant). The parent/caregiver filled out the parental self-checklist 3-4 times per week and the survey after the end of the program. The case study materials were gathered through with parent/caregiver. The case studies revealed that all of the parents responded that the parent's participation in music therapy helped to improve their interactions with their child. Furthermore, all parents became more responsive in interacting with their child through musical play, such as sing-a-long and movements. Second, musical parenting strategies encouraged parent-child interaction when practicing musical play at home. Third, the parent's self-checklist was shown to be effective material for increasing positive parent-child interaction. The self-checklist reminded the parents to practice using strategies in order to promote interaction with their child. Overall, it was found that the parent's participation in home-based musical play increased parent-child interaction and the musical parenting strategies enhanced parent-child interaction. / Dissertation/Thesis / M.M. Music Therapy 2013