At the South by Southwest Festival in Austin tonight, there will be the US premiere of Max Richter’s Sleep, an 8-hour, 31 movement concert event that joins the comparatively short list of works that are orders of magnitude longer than normal concert fare. They test the strength and stamina of not only the performers, but also the audience. Sleep has the advantage of being written with the idea of mimicking what the brain does when people drift off into sleep.

Despite a long-standing story from an early biography of Bach, the Goldberg Variations probably weren’t written for a court musician to play for his patron who suffered from insomnia. But the approach of 32 variations on an aria’s bassline is in keeping with some of the other long works in the canon. Taking the time to explore and not be in any hurry to get to the end. Glenn Gould famously recorded the set twice, in 1955 and 1981, slowing down considerably for the latter. In 1930, the British composer and pianist Kaikhosru Shapurji Sorabji created the epic solo piano work Opus Clavicembalisticum. It takes about 5 hours to play (for 36 years, Sorabji banned the performance of his works without his consent, based on a sub-par treatment it received in a recital) and in just one of the movements, a Passacaglia, there is a theme and 81 variations. That was through-composed, though, unlike Erik Satie’s Vexations, in which the eccentric composer asks that a one minute long theme be repeated 840 times. Every now and then a performance of the work is staged, usually with many performers in rotation on the piano bench. Wagner’s Ring Cycle takes about 15 hours, depending on the production (one is coming to San Francisco Opera this summer) and the long-view approach to the four interconnected operas is hinted at in the way he begins the first of them, Das Rheingold, with five minutes or more of a single arpeggiated E-flat chord, that builds over time. Leif Inge elongated a pre-existing recording of Beethoven’s Ninth Symphony, using computer software to stretch the piece to fit 24 hours. It’s called 9 Beet Stretch, and the pitches are maintained, and so the effect is one of an ever evolving blur. But the longest of them all is no doubt the 639 year performance underway in a church in Halberstadt, Germany, where an organ is playing (by means of weights on the keys) a work by John Cage (of course) called Organ2: ASLSP, for ‘As Slow as Possible’. The last time the chord changed was 2013, and the next one is scheduled for 2020.