The southern-fried jam band Gov’t Mule is celebrating two decades of genre- and face-melting music with another big tour and the release of several epic sets from years gone by, including two shows from 1999 with jazz-guitar master John Scofield. Scofield joins the band for tonight’s show at the State Theatre (142 High St., Portland) at 8 p.m. Tix: $30-$35 (all ages). 800-745-3000. statetheatreportland.com.