test('Have expected pitches for C Major 6 add 9 chord', () => {
    const expectedPitches = [Pitch.C, Pitch.E, Pitch.G, Pitch.A, Pitch.D];
    const chordPitches = Array.from(
      new ClosedChord(Pitch.C, ChordPattern.Major6Add9, Duration.Quarter, Octave.C4)
    );