Sum and difference tones of A220 and unison, just perfect fifth, and octave. Note that this is not produced through ring modulation of two notes, but is four separate notes.
*Tridecimal semitone on C. Just: 14:13 = 128.30 cents. Limit: 13-limit. Created in Sibelius with midi pitch bend on 73 for 128.125 cents rather than 128.30. New version a m2 on 7,73 for 128.2958984375 cents rather than 128.30.
Difference tones between Yankee Doodle in F and a drone on C. F=8/5 (1/1), G=9/5 (9/8), A440=1/1 (5/4), C=6/5 (3/2). Top and bottom line and difference tones.