Informal folk-singing performance

• Folk music shindig
• Community sing
• Folk-singing gathering
• Musical wingding

Wikipedia Word definitions in Wikipedia
Hootenanny is a Scottish word meaning "celebration" and/or "party". With the Scots being one of the biggest groups of settlers in the Appalachian region of North America (bringing with them their whisky-making tradition and methods, leading to the area's ...

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
hootenanny \hoot"en*an*ny\ n. An informal social gathering or concert featuring mostly folk songs, sometimes dancing, and where the audience often participates in the singing. [PJC] Same as whatchamacallit ; a thingumbob. [Obsolescent, chiefly dial.]

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
"informal session of folk musicians," 1940, American English, earlier "a gadget" (1927), of unknown origin, perhaps a nonsense word.\n\nAnother device used by the professional car thief, and one recently developed to perfection, according to a large Chicago ...