Tesseract (often stylized as TesseracT) are an English progressive metal band from Milton Keynes. The band, formed in 2003, consists of Daniel Tompkins (lead vocals), Alec "Acle" Kahney (lead guitar and producer), James Monteith (rhythm guitar), Amos Williams (bass, backing vocals) and Jay Postones (drums, percussion). The band is currently signed to Kscope. They are credited as one of the bands to pioneer the djent movement in progressive metal. As of 2022, Tesseract have released four studio albums: One, Altered State, Polaris and Sonder, as well as two live albums, Odyssey/Scala and Portals, and the extended plays Concealing Fate, Perspective and Errai.