The cast of Spamalot, at Fair Park Music Hall as part of the national tour of the hit musical, will be performing at another theater in town this weekend. On Sunday, members will gather at Contemporary Theatre of Dallas’ home at the Greenville Center for the Arts for a one-night only cabaret benefiting AIDS Arms. A $5 donation at the door — and all tips offered to the performers — go directly to AIDS Arms. There will also be a silent auction of Spamalot memorabilia (cocoanuts? a herring? You have to show up to find out). Doors open at 8 p.m., with the show starting at 8:30 p.m. 5601 Sears St.