string cheese does definitely have an organ, kyle hollingsworth and he is unbelievable...check out these guys if you get a chance...
http://www.cosmicsweatsociety.com
there playing lake worth this upcoming friday night...the organ player is great...they are more funky...
for more strings check out ekoostik hookah, donna the buffalo, the drew emmitt band(from leftover salmon), widespread panic(more of southern rock sound)