play around with Modes too...
http://en.wikipedia.org/wiki/Musical_mode
there are 7.. u can hear what they sound like by going up and down all the white notes only
C up to C is what the 1st mode (lydian) sounds like from C
D up to D is the 2nd sounds like from D
E to E - 3rd. from E
F to F ..from F
G to G.. from G
A - A..
B - B ..
each has its own character
use a pitch midi plugin to change the inputted notes... so u can play C- C (pr whatever) on the keyboard, and pitch it up to actually be the lydian mode from G or something.
lydian is pretty boring tho... i like the aeolian :) u can do some nice and melodic arpeggios if u get used to the modes!
sorry if i explained this totally arseways...