Re: Questions about modes
OK, to answer your simple question first - the 3rd of a chord is what defines it as major or minor.
(I think of scales as intervals rather than notes, so if you use notes then in C, 1 = C, 2 = D, 3 = E, 4 = F, 5 = G, 6 = A, 7 = B)
major chord: 1 3 5
minor chord: 1 b3 5
maj 7th: 1 3 5 7
dom 7th: 1 3 5 b7
minor 7th: 1 b3 5 b7
major 6th: 1 3 5 6
minor 6th: 1 b3 5 6
etc. etc. see how all the minor chords have a b3?
Scales follow chords, so to determine if a scale/mode is minor just check the 3rd.
Next question!
Modes only make sense over a certain note, so you have to be very aware of the chords/bass lines that you're playing over. For example, if you're playing a simple progression (I - IV - V) in C and you stay in the C major scale through the whole thing you're actually playing C Ionian (over the I chord - 1 2 3 4 5 6 7), F Lydian (over the IV chord - 1 2 3 #4 5 6 7), and G Mixolydian (over the V chord - 1 2 3 4 5 6 b7). This can get VERY confusing VERY quickly. Rather than spend hours upon hours memorizing scale/modal patterns and trying to force them into my head, what I do to keep track of it all is a little different.
I like to improvise over a progression by first locating the chord tones that I'm playing over. Over the simple example that I previously used, I look at what tones the chords have in them:
I - IV - V in C
I = C major = CEG
IV = F major = FAC
V = G major = GBD
Now after learning the position of all of those notes on the fretboard, I can generally stumble through the solo and I won't be playing any bad notes. However, if I want to play somthing that sounds cool then I'll use extra notes. This is where stuff starts getting cool . . . I'll try out adding 7ths, 9ths, 4ths, 6ths, b7ths, b6ths, etc. to add some spice to the regular progression. Now let's look at the modes:
1 2 3 #4 5 6 7 Lydian
1 2 3 4 5 6 7 Ionian
1 2 3 4 5 6 b7 Mixolydian
1 2 b3 4 5 b6 7 Dorian
1 2 b3 4 5 b6 b7 Aeolian
1 b2 b3 4 5 b6 b7 Phrygian
1 b2 b3 4 b5 b6 b7 Locrian
If you end up liking the way that a b7 sounds against the major chord (1 3 5) you're playing on then you're playing in Mixolydian. If you like the way that a
4th and 7th sound when you're playing against a major chord then you're playing in Ionian. Does it matter what mode you're in? NO! You're just picking notes that sound good to you.
How do you know what notes to pick???
Well, different styles of music follow certain rules. For example . . . blues tunes often make use of certain combinations of notes. Over a major chord in a blues tune you might play these special notes:
b5 - this is the so called 'blues note'. The next time you're playing a pentatonic lick, throw in a couple of b5s and listen to how bluesy what you're playing sounds.
b7 - blues tunes make heavy use of the b7, so it's a good note to throw in there.
b3 - even though the chord you're playing over is major, playing a b3 and bending it up to the major third gives a nice bluesy feel.
6 - The 6th sounds sweet when you play it in the right context in a blues tune.
Other genres have special notes that are often thrown in as well. Maybe you're playing jazz over a more complicated tune:
Dm7 - Gm7 - Cm9 - Fmaj7
Dm7 - 1 b3 5 b7
Gm7 - 1 b3 5 b7
Cm9 - 1 b3 5 b7 b9
Fmaj7- 1 3 5 7
This one is even easier to play! The chords have already given you most of the colour notes that you need to solo!
I guess the point that I'm trying to show you is that it's not necessary to even think about modes. Just concentrate on sounds and notes and you'll use them automatically.
I love to learn and figure things out for myself, but I've never taken a guitar lesson in my life. If I'm wrong, or way off base here someone please point it out!