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
   interval
           9:8             9:8        256:243         9:8            9:8             9:8        256:243
Just
1:1
9:8
5:4
4:3
3:2
5:3
15:8
2:1
interval
           9:8           10:9            16:15        9:8             9:8             9:8           16:15
Equal
1:1
1.1225:1
1.2600:1
1.335:1
1.4983:1
1.6818:1
1.8878:1
2:1
interval
           21/6            21/6               21/12            21/6              21/6              21/6              21/6    
Table 1  The diatonic scale in three intonation schemes, Pythagorean, Just and Equal Temperament.  For each intonation, the first row gives the frequency ratio from the tonic C to the given note.  The second row in each case gives the frequency ratio between adjacent diatonic pitches.