Enigmatic British band Sleep Token combine post-rock, post-classical, and post-metal tropes with soulful indie pop vocals into a blend that sounds like nothing else. They released their innovative debut album, Sundowning, in 2019. The group appeared in 2016 with the self-released single "One." Their schtick was unique, to say the least: Fronted by a mysterious masked figure known only as Vessel and professing to worship an ancient deity called Sleep, they framed themselves as a kind of cult whose songs were all acts of worship to the deity. Sleep Token's music was equally original, blending tranquil post-rock instrumentation and soulful falsetto vocals with sudden eruptions of tech-metal brutality. Frenzied online speculation ensued as to the identity of the members, with the likes of Sam Smith, Hozier, and Bastille's Dan Smith being put forward as candidates. The influence of artists like Deftones, Meshuggah, Explosions in the Sky, Bon Iver, and Ólafur Arnalds was apparent, but the whole was greater than the sum of its parts. Sleep Token signed to Basick for their 2017 single "Two," then self-released a few more singles in 2018 before making the move to the Universal-distributed Spinefarm for their 2019 debut full-length album, Sundowning. In an unusual move, every track off the LP was issued as a digital single prior to its release, over a period of six months. With a bigger budget than before, the album presented a widescreen version of the band's sound, with more electronic elements, a pronounced R&B edge to the vocals, and a sludgier post-metal feel to the heavier parts. A deluxe version of Sundowning featuring four extra tracks appeared in 2020.