Extracting a Composition class from TuneComposer would delegate many responsibilities. A version of this method would belong there too: https://github.com/WhitmanSWDesignSpring2018/project-5-8-teamalfalfa/blob/e1cce2b8b11fa6a476777c802d5d98fdb704f08b/src/tunecomposer/UndoRedo.java#L22
Extracting a Composition class from TuneComposer would delegate many responsibilities.
A version of this method would belong there too:
project-5-8-teamalfalfa/src/tunecomposer/UndoRedo.java
Line 22 in e1cce2b