public void PreviousNote_Test()
{
Assert.Equal(Notes.B, Notes.C.PreviousNote);
Assert.Equal(Notes.C, Notes.D.PreviousNote);
Assert.Equal(Notes.D, Notes.E.PreviousNote);
Assert.Equal(Notes.E, Notes.F.PreviousNote);
Assert.Equal(Notes.F, Notes.G.PreviousNote);
Assert.Equal(Notes.G, Notes.A.PreviousNote);
Assert.Equal(Notes.A, Notes.B.PreviousNote);
}