The Great American Beer Hall invites early jazz fans from everywhere to its first Mardi Gras Bash, an afternoon of New Orleans-flavored songs performed by two fabulous New England bands. Local favorites Annie and the Fur Trappers will team up with New Hampshire-based Soggy Po’ Boys for this hopping BASH, just days before Fat Tuesday. Food and drink will be available for purchase. Admission is free, but attendees are encouraged to make a donation to support this summer’s Bay State Hot Jazz Festival (the BASH Jazz Festival, formerly the Medford Trad Jazz Festival), which will feature eight bands on the weekend of August 23-24 at the Condon Shell.