Watch the Building Chords online guitar lesson by Fareed Haque from Modal Improv Survival Guide
One of the nice things about the modal approach is the way it can help us build unique chords and chord voicings. Typically jazz chords are built by stacking thirds, and we can do this to build very typical sounding jazz chords. However, unlike an arpeggio based Bebop approach we can also easily stack notes in a mode using any other interval we like...so we can create chords by stacking 4ths or stacking 5ths. Also we can simply find an interval formula that we like - say a 4th and a 2nd ( C, F and G ) and move that thru a mode: C,F,G becomes D,G,A becomes E,A,B.
Keep in mind that we will stack intervals DIATONICALLY, that is we will always stay in the scale to build our chords. So a 4th in the key of C can be C to F, D to G, E to A, AND F to B. Even tho this is an augmented 4th it still is part of the C scale so its one of the diatonic 4ths in C.