Introducing major key based songs would do a lot to improve the mood of the music. In general, major keys are used for a lot of pop music...for example, both t

Introducing major key based songs would do a lot to improve the mood of the music. 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.