[gersdal]

Hi,
Chords are built up from the major scale, or at least that is a way of understanding them. The major chord is built up by the 1-3-5 triad of the major scale, and the minor chord of the 1-3-5 triad of the minor scale. The sus chord has an 4'th tone of the scale instead of the third. The 7 chord has the b7 added. The 9 chord has the b7'th and the 9'th added. The 11 chord the b7'th, 9'th and the 11'th added. The 13 chord has the b7'th, 9'th, the 11'th and the 13'th added

Example from the C-major scale
1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13
C - D - E - F - G - A - B - C - D - E - F - G - A

C chord: C-E-G (the 1-3-5)
C7 : C-E-G-Bb (1-3-5-b7)
Csus : C-F-G (1-4-5)
C13 : C-E-G-Bb-D-F-A (1-3-5-b7-9-11-13)

A minor chord has a lowerd third (b3), the identification of a minor chord. For the C minor chord that will mean C-Eb-G (1-b3-5). The m7, m9 etc is built up as above, but with the b3 indicating a minor chord.

Hope this helps.