Part of the concept of this group is that we can play "a little bit of any style of music". 
There is a small amount of music that is already written for this type of group.
Much of what this group does we arrange or compose ourselves.

Another thing we frequently do is take a lead-sheet-- that is written melody and chords-- and then improvise parts (eg, make up bass lines, comp, solo etc).  

Though not limited to this (and we have even sight-read on gigs), here is a list music we frequently have in our repertoire.  Note, no Christmas Music included in this list (though of course we play them.  And theoretically can play anything!):