Two experiments investigated the effects of a music and movement (M&M) programme on healthy first-time mothers and their 2-6-month-old infants over a five-week period. Experiment 1 (N?=?96) examined the effects of the M&M activities and the face-to-face (F2F) social contact of a group instruction method on the perception of mothers' interactions with their infants and maternal postnatal attachment. Generally, M&M increased mothers' interactions with their infants specific to music-type activities and mothers' attachment to their infants. Contrary results occurred for No M&M-control group mothers. The presence/absence of F2F had no effect. Experiment 2 ("N"?=?44) focused on behavioural effects of M&M on mothers' infant-directed speech (IDS) and mother-infant reciprocity. M&M increased dyadic reciprocity, and increased the duration, mean pitch and pitch range of mothers' IDS. Without M&M a decrease in attentional characteristics of mothers' IDS and dyadic reciprocity occurred.