I don't know enough about music theory to give you more detail than that, but is there a way you can add more upbeat songs, to get my mood up, energy up, motivation kicking in? Listening to these, I kind of want to take a nap.
The most amazing feelings often wash over me, in fact, while listening to these incredible composers...after a while the "atonal" notes will suddenly "snap" into place while my brain is somehow making sense of the music without my help.
It is truly a sublime moment when this magic occurs, and I'll often laugh out loud as the sudden transition from melodic confusion to understanding occurs.
In general, major keys are used for a lot of pop music...for example, both the Beatles and Nirvana wrote almost all their hits using major keys (Let It Be and Smells Like Teen Spirit), while ballads and more sad and "moody" music (ie Stairway to Heaven/Zeppelin and Unforgiven/Metallica) will be written in minors.
Also, tempo is important to add to the"upbeatness" of a piece...it would an interesting addition to this wonderful program to add switches for major/minor key and tempo.