“…Investigations of MSB must consider the bidirectionality of the interaction and the needs and goals of both social partners. For example, musical activities between parents and their child with a neurodevelopmental disability are increasingly recognized as modulating parent behaviors such as parent responsiveness (e.g., physically supporting child's play through contingent imitation) (Boorom, Muñoz, Xin, Watson, & Lense, 2020; Thompson, Shanahan, & Gordon, 2019) and parent mood (Williams, Berthelsen, Nicholson, Walker, & Abad, 2012), thus enhancing the likelihood of child engagement downstream. Music and song may be a particularly meaningful platform for social communication in light of the altered language and social communication abilities in ASD and Williams syndrome (Mervis & Velleman, 2011; Tager-Flusberg, 2000).…”