Smitty is an indispensable part of the band. That's because he's responsible for setting up and maintaining the keg of beer! The band is entirely fueled on beer, and without Smitty the band would probably fade into the sunset.
In all fairness, Smitty does a lot more than just maintain the keg: he helps move, set up, and take down equipment, fixes anything that might be broken, and doubles (triples?) as our electrician.
But all that pales in existence compared to the fundamental task of lubricating the band! ("Anyone ready for another one?...")