This study investigated how and when teachers used music in preschool classrooms throughout the day. Direct classroom observations were conducted to determine preschool teachers' use of music in four Head Start classrooms and one private preschool classroom for a total of 24 hours of observation in each classroom. Music was observed to be used 6.5 times per hour on average. All teachers used music most frequently to scaffold children's learning both in academic skill and social skill areas, and second most frequently to scaffold routine activities such as cleaning up and transitions to new activities. All teachers used music most frequently during group time. Music was used most frequently at group times outside times specifically set aside for music and movement. Researchers, practitioners, parents and teacher preparation professionals need to be aware of these findings in order to fully appreciate the broad experience that teachers and children have with music on a daily basis in preschool. (Contains 4 tables.)