Here’s a handy table of interval ratios for three tuning systems:
| System |
C |
D |
E |
F |
G |
A |
B |
C’ |
| Pythagorean |
1/1 |
9/8 |
81/64 |
4/3 |
3/2 |
27/16 |
243/128 |
2/1 |
| Just Intonation |
1/1 |
9/8 |
5/4 |
4/3 |
3/2 |
5/3 |
15/8 |
2/1 |
| Equal Temperament |
1/1 |
2^(2/12) |
2^(4/12) |
2^(5/12) |
2^(7/12) |
2^(9/12) |
2^(11/12) |
2/1 |