Historical clue formulations

• Louisiana music typically featuring an accordion — 2020-06-29
• Offshoot of the blues — 2019-03-02
• Bayou genre — 2017-12-30
• Music style featuring accordions — 2016-04-22
• Style associated with washboards — 2010-10-29
• Grammy category starting in 2007 — 2009-11-13
• Louisiana music — 2004-02-01