Key PointsQuestionWhat is the effect of parent-led, infant-directed singing—initiated in the neonatal intensive care unit with support from a music therapist and extending 6 months after discharge—on parent-infant bonding at 6 and 12 months’ infant-corrected age?FindingsIn this randomized clinical trial involving 213 families, mothers engaging in parent-led, infant-directed singing reported similar parent-infant bonding at 6 and 12 months’ corrected age as mothers receiving standard care only.MeaningThese results suggest that, although safe and accepted by parents, parent-led, infant-directed singing was no more effective at improving mother-infant bonding than standard care.