If you have read the (modes explained thred),please disregard it because it is NOT how most guitarist use the modes.
I sometimes use a minor mode over a major chord or progression but only in certian circumstances.
I should have known that it would cause more confusion than clarity.
The thred was aimed for begginers and it will do nothing but CONFUSE them COMPLETELY.
So please accept my appology...
Now lets start fresh.Many begginers know where the modes come from but dont understand how to use the modes.,so lets take a sample progression first and explain how we can use a mode over it.
The progression will be C...F...Am...Em...Dm...G7...F..This is a completely diatonic(all notes and chords belong to the key) progression.
Now you have 3 choices here to play over these changes(apart form arpeggios etc.).
1.play the C major scale over all the chords
2.play the diatonic modes over the respective chords(which is just like playing C major over all the chords)PLEASE NOTE: you are NOT using the modes effectively if you play the modes that are diatonic to the key.eg:the key is Cmajor and the chord is Dm and you play D dorian.
This is the same as playing C major because all the notes of D dorian are diatonic to Cmajor.
3.introduce modes that are not diatonic to the chords.(prefered choice)
Choice no.3 is the prefered one because it will give us some nice outside notes to color the otherwise diatonic progression.
So we start with the C chord.What are our options?
2.C lydian(diatonic to Gmajor)
3.Cmixolydian(diatonic to Fmajor)
Why are these our options?
Because these modes are major modes and the chord is a major one and the lydian and the mixolydian have only ONE note different in comparison with Cmajor.
The lydian has the F# and the mixolydian has the Bb.
These 2 notes create a dissonance (tension)in the key of C because they are not apart of the key,but they add a welcome bit of variety from the other (diatonic ones).
BUT use them as passing notes and dont sustain them too long,becuse they sound much better when they resolve(move to),the NEAREST note that is apart of the key.(especially when it is chord tone )
Now the F chord.
Our options are
1.F.lydian(diatonic to Cmajor)
2.F ionian (diatonic to Fmajor)
3.Fmixloydian(diatonic to Bb major)
The lydian is diatonic so there will be no outside notes,but the ionian has a Bb and the mixolydian has a Bb and a Eb.
Now the Am.
1.A aeolian(diatonic to C major)
2.A dorian(diatonic to G major)
3.A phrygian (diatonic to Fmajor)
the A aeolian is a poor choice because it brings in nothing new.
The the dorian has a F# and the A phrygian has a Bb.
Now again these notes sound strange to the key of C major but BEAUTIFUL when they move to a chord tone or diatonic note.
I wont go through the rest because you should get the idea by now.
BUT just remember that if you play the modes that are diatonic to the key and that corespond to the chord of the moment you are not playing modally,all you are donig is agreeinig completely with the key and you may as well play the scale of the key (in this case Cmajor).