A very popular musical form during the calssic period was doubtless, the Sonata form. It is a musical form were two themes appear joined together with a develepment section. It is probably the form that gave birth to what we can hear in popular songs.

The sonata presents an A theme followed by a B theme. Both parts repeat and a development section follows, a melody which in a pop song would be called the Middle C.

Immediatly afetrwards, the A theme appears again followed by the B theme, both of them presents variations of some type: rythmically, melodically or in its harmony.

The following example is a piano piece that took as main reference the Sonatina for piano in F major by Muzio Clemnti, whose form goes like shown in the image:

Our composition presents somewhat a more contemporary idea, where the transition between the 1st and 2nd themes is in the parallel major of F instead of F#m. The development goes changing mode between D an Dm.

The recapitualtion is presented in C major instead of A major where it began. Oure readers can listen to the piece on the following link:

The score, is yours to try: