ok i read the music theory faq and understand everything i learned from it except modes.

can someone explain them for me, when to use them (if thats possible), and anything else about modes.

"The mind is its own place, and in itself

Can make a Heav'n of Hell, a Hell of Heav'n"

- John Milton, Paradise Lost
no one? i read it again but i still dont get it..

"The mind is its own place, and in itself

Can make a Heav'n of Hell, a Hell of Heav'n"

- John Milton, Paradise Lost
Give it more than half an hour...the experts don't spend their entire day on here...
Here is one of our experts discussing modes.

First of all, a mode is a way of playing a scale. There are 7 basic modes, all based on the major scale. If you don't know the major scale, learn it ASAP. The intervals are W W H W W W H.

Anyways, since there are 7 notes in the major scale, you can have 7 different root notes (or starting points) and still be in the same key. For the purpose of this lesson I'll be using the key of C, because it has no flats and no sharps, and is one of the most common keys.

First of all, start thinking of notes as scale degrees:

  Note: C D E F G A B C
Degree: 1 2 3 4 5 6 7 1

The names of the modes, in order, are Ionian, Dorian, Phrygian, Lydian, Mixolydian, Aeolian, and Locrian, and they start on their respective scale degrees.

Starting on the first degree, you get 1 2 3 4 5 6 7 1, which is Ionian. Also the major scale.

Starting on the second degree, your notes are D E F G A B C D. This is the Dorian mode. Its formula is 1 2 b3 4 5 6 b7 1. Here's why:

 Degrees: 1 2 3  4 5 6 7  1
 D scale: D E F# G A B C# D

D Dorian: D E F  G A B C  D
 Degrees: 1 2 b3 4 5 6 b7 1

You should be able to see how the F# was flatted down to F natural and C# down to C natural. That is how each mode's formula is found.

The third mode is Phrygian, its forumula is 1 b2 b3 4 5 b6 b7 1. In the key of C, the notes would be E F G A B C D E = E Phrygian.

The fourth is Lydian. Formula is 1 2 3 #4 5 6 7 1.

5th is Mixolydian, 1 2 3 4 5 6 b7 1.

6th is Aeolian, or the natural minor scale. 1 2 b3 4 5 b6 b7 1.

7th is Locrian, which is a half diminished scale. 1 b2 b3 4 b5 b6 b7 1.

Therefore, the 7 modes in the key of C are:
C Ionian
D Dorian
E Phrygian
F Lydian
G Mixolydian
A Aeolian
B Locrian
Take a scale, start playing on the root note(C). That's the Major Scale/Ionian mode. Make what would normally be the second note of the scale(D). That's the ii mode/Dorian mode. etc. As simple as that. That's called a relative mode, because it's relative to the root note. When you do this there are plenty of other things that happen(such as because you changed the tonic(the note you start counting from) your note intervals are going to change).

The other way to use them are parallel modes, that is you use a tonic but move the root note to match the scale root note. C Ionian, C Dorian, C Phyrgian, etc.

As to when to use them, search around from modal music. It's been answered plenty here and elsewhere.