Singing familiar songs to a distressed baby brings comfort—more so than unfamiliar songs or expressive talking. Thus, singing to babies plays an important role in creating the parent-child relationship. A repertoire of familiar songs sung together can be a source of comfort in moments of distress. In an experiment conducted in Canada, 136 babies aged eight or 10 months were videoed as a parent provided comfort by singing a familiar song, singing an unfamiliar song, or talking expressively. Each parent was asked to play with the child for two minutes, then present a blank face to the child (the “still face procedure”) for one minute (or less if the child started getting really upset), then reunite with the child for two minutes by means of singing or speaking. The video recordings showed that, particularly in the first 30 seconds, the babies paid more attention to the parent, smiled more and …