Well, just as I thought I was nailing down modes, some doubts started popping into my mind. I hope you guys can help.
By listening, playing and studying a lot of music (mainly Satriani's) I've been able to understand the basics of how modes work and what they sound like. It's obviously something that can't be easily explained and you actually have to listen to it in order to understand it. Anyway, this has all been said before so here are my doubts.
Most of the riffs, licks, solos, I've found are always in a given mode which I'm able to recognise by looking at the intervals. However, I've noticed that I still haven't been able to find the locrian mode anywhere. I guess it has to be a very strange mode due to that lowered fifth and the root corresponding to the seventh degree of the corresponding ionian (major) scale. Nevertheless I find it a bit strange that I haven't been able to find it yet, after all Satch's music is not exactly simple. I'd appreciate if anyone could indicate me any musical examples where I can listen to this mode and any useful information about it.
My other doubt is about how modes are played over chords. I don't know how to explain this doubt of mine since I'm not too sure really what I'm not understanding here but I'll do my best for you to follow me. What I don't get is if I should keep in mind the chord over which I'm playing or the tonality of the song at that moment. Yes, many times this will be the same but if for example you have a simple chord progression in C major (C major, F major, G dominant seventh) where you would probably play C ionian. Does this mean that when the chord changes to G7 the scale will turn into G mixolydian or will it still be C ionian (because that's the obvious tonality of that progression)???
I hope I made myself clear enough and I'll appreciate any help you guys can give me. THX