Mathemagical Music, page-9

All music has a mathematical equasion to it.
Starting with the Major scale.
The arpeggios of the major scale and there are many but the basics are
1 3 5
This arpeggio denotes whether it is a major or a minor scale and arpeggio.
1357 denotes a 7th arpeggio
13579 denotes a 9th arpeggio.

In the key of C the notes are:
1 2 3 4 5 6 7 8
c d e f g a b c

Each note equates to a particular frequency for instances a note often used to tune a guitar is A 440hz.
Each not of a scale represents its own scale as well as its own chord so the whole algo is used again.