Widespread Panic

Widespread Panic has been playing its swampy jam-rock since the mid-’80s, when there was no organized jam scene for them to lean on. The emergence of jam in the late-’90s as its own genrewith its own business modelturned the once-obscure band into a lucrative touring machine, and in recent years the band has had to alter its tours to account for its many sold-out shows. After doing a sold-out show at the Riverside Theater, for instance, the band planned ahead and booked two shows at the Riverside last year. For this latest go-round, the band tops themselves again: They’ll be doing three shows. They play the second tonight at 8 p.m. at the Riverside Theater.