Sigur Rós have just released the fourth volume of their ongoing endless ambient playlist, Liminal, in conjunction with their biggest soundbath to date: a performance featuring Jónsi, Alex Somers and Paul Corley tonight at Hyde Park's Great Oak Stage.

The Liminal Sleep playlist, designed to help listeners drift off into peaceful slumber, has launched exclusively on the sleep, meditation, and relaxation app Calm.

The material on Liminal Sleep draws upon some of Sigur Rós's most deeply ambient material from the ( ), Takk..., Með suð, and Valtari albums, including reworkings of "Sé lest," "Glósóli," "Svo Hljótt," "Untitled #9," "Góðan daginn," "Varúð," "Dauðalogn," "All Alright," and "Valtari." With over 50 million downloads and 700,000 + 5-star reviews, Calm is the world's #1 app for sleep, meditation and relaxation.

The Liminal soundbath events offer an alternative way of experiencing Sigur Rós in the live environment - one in which the aim is to slow down, focus upon one's senses, and to be present in the moment. Liminal brings together music from various strands of the band's career - not only the back catalogue and new material, but also collaborations, solo projects, and film scores. It presents a multi-faceted way to experience the entireSigur Rós creative universe.

Regarding the new volume, the band state: "We like the fact that sleep remains defiantly mysterious; something we all do - all need to do - but can't ever get fully inside. We don't really think about it, we downgrade it and we don't do it enough. And even though there could be something paradoxical about making music to sleep to, when you consider the cycles, plateaus and transitional states of the sleeping brain, as well as the mental processing, body maintenance and sheer, crazy freedom of the dreaming mind, you can understand why sleep has been such fertile ground for art since art began. This playlist is a modest attempt to mirror the journey of a sleep cycle, with its curves, steady states and natural transitions."

Fans are encouraged to come along with an open mind, and to settle down on the grass with a comfortable blanket to soak up a summer evening that's accompanied by ever-evolving minimalist soundscapes. The music will be accompanied by newly commissioned visuals which will be displayed on some of the world's largest video screens. The event will commence with a screening of Sigur Rós's celebrated Route One slow TV broadcast from 2016, which depicts a journey around Iceland's famous Route 1 ring road. Calm's Head of Mindfulness, Tamara Levitt, will then lead a guided meditation ahead of Sigur Rós's sound bath performance.