Alyster's Symphony

This is an Alvin and The Chipmunks fanfiction with my own character being introduced to it. Plotline goes as followed... Alvin and his brothers, Simon and Theodore, along with the Chipettes made names for themselves as singing chipmunks across the world and at their school. However, when the mysterious Alyster Heartstone joins their school, Alvin and his group are introduced to another famous chipmunk that tries to stay under the radar.