Write non happy path tests for New Tune

[ryaustin]

What happens if a user types C minus, or C -?
What do you want to happen?
Write a test as proof.

• When a user types any unacceptable input my desired behavior happens successfully.

Key question: Is the user experience affected? If it is, what is the experience you would like the user to have (don't think of your skills as they are today, think of future Jeff here).