The dreamy music at the beginning and a little bit further on is the famous Canon in D written by Johann Pachelbel around 1680.
The pop music that is played after the class when the soldiers run out is Doo-wah-diddy, originally by the Exciters but made famous by Manfred Mann in 1964. Later, at the folk dance class Hippy hippy shake performed by the Swinging Blue Jeans and brought out in 1963 is played.