ok - so if I tie that back into Jarkko's reply, and try to work out the general rule, is it correct to describe it all as follows?

If I take any major key, I can work through the notes in that scale to identify all the modes as follows:

Staying with the key of Bb:

1st mode: Bb ionian (major). Bb-C-D-Eb-F-G-A

2nd mode: C dorian. Same scale, but start on the 2 note in the key (C)

3rd Mode: D phrygian. Same scale, but start on the major 3 note in the key (D)

4th mode: Eb lydian. Same scale, but start on the 4 note in the key (Eb)

5th mode: F mixolydian. Same scale, but start on the 5 note in the key (F)

6th mode: G aeolian (minor). Same scale, but start on the major 6 note in the key (G)

7th mode: A locrian. Same scale, but start on the major 7 note in the key (A)

Then if we looked at the key of C, it would be C ionian, D dorian, E phrygian, F lydian, and so on...