Instead of 'getting the band back together'...
Which they did in the first film, what they could've done in this one was bring together a whole new band due to the original members gone off to new and more prosperous careers and would not rejoin Elwood (after what happened last time), so Elwood, along with John Goodman and the kid set about the daunting task of finding new musicians. That would've been a bit more original than just rehashing the first movie.