Originally Posted by: Cryptic ExcretionsI'm guessing people use Ionian instead of diatonic major scale for a similar reason that they would say Bb instead of A# when playing in F Major.

Is spot on. Try not to get too caught up on the name's of things. Being aware of their various names is useful, but as long as you know yourself what mode you need to play, that's the main thing.

On a lingustic note, I suspect, (and I'd be interested to know if anyone out that has some knowledge) that Ionian is a non-English term, (though I wouldn't like to guess what language), while Diatonic Major is the "English" (yes, yes, I know it's part Latin or Greek, but stay with me here!) term. Same reason we have call chicken's hens and hen's chickens.....

Why've I a feeling the only person I'm interesting is myself?.... Ah well! :rolleyes: