There're several different acts currently charting as The Sundowners:
1.) The Sundowners were a country-western trio from Chicago, 1959-1989. They included guitarist Don Walls, guitarist Bob Boyd and bassist Curt Delaney. Promoting their retrospective CD, Bloodshot Revival proclaimed The Sundowners knew more than 15,000 songs, playing about 7,000 songs annually.
2.) A very early collaboration between Will Oldham and Bill Callahan.
3.) A 1960s Sunshine Pop group, notable today for having their song "Always You" compiled.
4.) An early band led by Tom Petty
5) Sonny Day and the Sundowners came together in Auckland, New Zealand around 1960. The band had numerous changes in lineup, but long-time members included Sonny Day on rhythm guitar, Bob Wynyard on lead, Teddy Toi on bass, Max Purdy on piano, Lloyd Tangaio on sax, and Graeme 'Trixie' Willoughby and Lionel Kennedy on drums.
6) A Liverpool band featuring James Skelly of The Coral on vocals in early demos.
7) A Minneapolis DIY punk band on Dirt Cult Records