Data collection
TD
Treatment delivery analysis was based on recordings from approximately 10% of each therapist’s participants, evaluated by the corresponding music therapist and two external raters per therapist. Sessions during NICU stay were audio recorded, and during follow-up were video recorded for all sites, except one that could not obtain permission to video record. Music therapists were responsible for audio/video recording their own sessions. Video instructions were to aim for a frame that showed both parent(s) and infant. Participants for TD analysis were randomly selected using 