Mates of State are an American indie rock duo, who have been active since 1997 when they formed in Lawrence, Kansas, United States. The group is composed of the husband-and-wife team Kori Gardner (vocals, Electone and Hammond B-3 electric organs, Casio synthesizer, and Rhodes electric piano, piano, and occasional guitar) and Jason Hammel (vocals, drum set, glockenspiel, other percussion, and occasional Casio synthesizer).

Kori Gardner is one of the best female singers in modern music (and husband Jason is also no slouch). Their style is iconic — the effortless way their voices harmonize and volley back and forth, the movements within the song, the way they move from upbeat to pastoral so fluidly that you don't perceive it happening. Their instruments and voices all move as one piece, inseparable. Through the years, the textures have become more intricate, deeper. They've begun throwing in the occasional trumpet or guitar, but it is still stunning how much they can do with just keyboards and drums. They move so far within the limitations of the two-piece format that you can't even call it a limitation. It feels as natural as the standard rock-and-roll four-piece.

Mates garnered a rabid following beginning in 1998 and toured nearly non-stop for 15 years, performing all over the world including runs with NPR's This American Life, The Postal Service, The Strokes, Jimmy Eat World, Santigold and Death Cab for Cutie. They've also been seen on David Letterman, Coachella, Lollapalooza, Conan O'Brien, and Yo Gabba Gabba.

Mates' have released 7 full length albums (on labels including Barsuk and Polyvinyl) while simultaneously starting a family of 3 daughters(!) who travelled the world with them on tour. The Mates' paused touring from 2019-2024 to "give their girls a bit of an anchor through their teenage years," while continuing to write and explore to find their next musical phase. Then, in the summertime of 2024, they resumed full-on with a 17-date tour (in 17 days!). More touring and a new album will follow in 2025.