By A Mystery Man Writer
Interval Ear Training
Just Intonation, PDF, Interval (Music)
Compound Intervals, PDF, Interval (Music)
Just Intonation, PDF, Interval (Music)
Harmonic series (music) - Wikipedia
upload.wikimedia.org/wikipedia/commons/thumb/5/55/
Tritone - Wikipedia
4.5 Interval
The Song Grapher Project by CreCoProject on DeviantArt
Just intonation - Wikipedia