There are less expensive loop station stations then the jamman.
What you do it hit the foot pedal and play and then hit it again to stop and it loops what you have played. Or you can set it to just play once.
It comes with a few prerecorded things but not many.
So for example lets say you want to play a 12 bar blues. Just play the 12 bars and on the beat one of the thirteenth bar hit the pedal and you are done. That will loop over an over again. Then if you want you can put in a bass line or second rythm part or drums or what ever.
I just used it today for this, I simply played a B chord and then a A chord like Fire on the Mountain and now it loops Fire. I can play lead forever on it. Can you imagine trying to get someone to play that for that long while you try to experiment with some leads.
It comes with a 128 meg compact flash card. I bought a 2 gig card on ebay for $30 and can record 6 hours worth of music.
All this can be done on the fly
http://www.youtube.com/watch?v=jE9FSn-eovE
Here is the jamman
http://www.guitarcenter.com/shop/produc ... =103237590