1. Verify that sounds are played when clicking the three buttons. Clicking one button before the other sound has finished should
play the sounds simultaneously and independently.

2. Clicking the instrument C button may cause a clicking sound between the notes. This is normal.

3. Clicking the same button multiple times while still playing should restart the instrument to the beginning. Clicking the
instrument C button multiple times should cause more notes to be played at the same time. When enough notes are playing at the
same time, any clicking sound should go away.