Mates of State are an American indie pop duo, active since 1997.The group consists of the husband-and-wife team of Kori Gardner (vocals, organ, synthesizer, piano, electric piano, and occasional guitar) and Jason Hammel (vocals, drums, percussion, and occasional synthesizer). 　　As of 2015, the duo has released four EPs and seven full-length, studio albums. Their most recent album, Mountaintops, was released on September 13, 2011.