If ever a band name fully complied with all truth in advertising laws, it’s Big Sam’s Funky Nation. Singer-trombonist Big Sam Williams is indeed large, both physically and sonically, there’s Bootsy-level funk afoot, and the huge wall of Cajun-spiced sound produced by the five-man group does seem ambassadorial of their native New Orleans. Fans of psychedelic jam bands have embraced Big Sam’s funky dance vibe, which is perfect for spinners and trippers in between travelling roadshows by various members of the still-living Dead, so much so that their newest single, “Buzzin’,” made its internet debut on the Deadhead site Relix. It’s a fun track that shows a lot of playful virtuosity, especially in the interplay between Williams and singer-trumpeter Drew Baham, opening with a Framptonish talkbox and spinning a hyperactive tale of love and lust on the dance floor that wouldn’t sound out of place in any 1970s blaxploitation or hairy porn movie. The single previews a full-length called Songs in the Key of Funk that drops shortly before their May 18 appearance at Winstons in OB.