Simple 2000 Series Ultimate Vol. 27: Houkago no Love Beat

The main character is a high school girl trained in classical piano who has just transferred to a new high school, Aobadai Gakuen. On her first day, she gets lost and meets 4 boys there who are secretly practising as a band. She eventually becomes the songwriter for the band, using her classical background to create fresh melodies for the band to build on.