Take turns playing "anything". Easiest if you pick a MINOR key...
Out of 12 notes, all but 11 will fit
(the 12th being the flatted third that would turn it into a major key) -
AND other notes like 7th chords can add a blues or jazz or grunge rock feel!
Two basic EASY methods:
1. One person plays for about 3 minutes. Then the others play their instruments
to do fills. SURE- some things won't work!
But OH, the creativity that can come out of the pieces that do!
And it's so much fun to laugh at how HORRIBLE some experiments are!
2. Each person takes turn being the lead, with the others playing fills --
In Jazz Jams, the person who will lead often quickly pats their head :)
Feed the recorded music into your computer program and edit pieces you really like,
building new pieces around them.