Question: What musical style is performed by the professional group 'Straight No Chaser' who gained recognition when a video of theirs, 'The 12 days of Christmas' went viral and who subsequently landed a five-album deal before changing their name to Another Round?
Sentence (from "Straight No Chaser (group)"): Straight No Chaser (SNC) is a professional a cappella group which originated in 1996 at Indiana University.
Relevant evidence: Yes