Who's Next famously has its origins in Lifehouse, the rock opera Pete Townshend intended as the Who's sequel to Tommy. A concept in search of a narrative, the futuristic Lifehouse hinted at ideas that became part of the fabric of 21st-century culture, particularly "The Grid," which seems analogous to the internet and a numbing reliance on entertainment delivered through a system that suggested virtual reality. Townshend had ambitious plans concerning live concerts and a film, none of which materialized due to their complicated nature which, in turn, raised tension within the band. Frustrated, the band took highlights from the project into studios with producer Glyn Johns, creating the ruthlessly efficient Who's Next, nine songs that finally captured the might and muscle of the Who on record. Who's Next cemented the Who's popularity, particularly in America, turning into a rock perennial thanks to its biggest songs: "Baba O'Reilly," "Behind Blue Eyes" and "Won't Get Fooled Again." Those songs never disappeared from popular consciousness and Townshend couldn't leave Lifehouse behind either, tinkering with the story in subsequent solo albums and writing and occasionally dipping into his original demo archive, as when he assembled Lifehouse Chronicles in 2000. That box was anchored by a BBC Radio production of a radio play of Lifehouse aired in 1999 but it also had two discs of original demos. Many of those demos are on the Super Deluxe Edition of Who's Next, an 11-disc set that offers immersion in both Lifehouse lore and the Who's attempt to bring Townshend's vision to life. Thanks to Lifehouse Chronicles and a 2003 Deluxe reissue of Who's Next (not to mention other CD reissues and unofficial live bootlegs over the years), there's not a whole lot here that feels like a revelation. The truly unreleased cuts -- a lot of this amounts to new remixes of previously excavated bonus tracks -- amount to variations on familiar themes, all of which is welcome but not a surprise. Where this Super Deluxe Edition excels is in providing context. The Townshend demos are grouped as a pair, then the fruitful Record Plant sessions with Johns occupy one disc and the contentious Olympic Sound Sessions from 1970-1972 are another, while all the stray singles -- and there were a lot, including "The Seeker," "Let's See Action," "Join Together," and "Long Live Rock" -- are on another. Hearing these sessions broken down this way does illustrate how the Who were at a peak during this period: maybe they were battling in the studio but even the Olympic Sound recordings crackle with their distinct chemistry. The live sets -- one held at London's Young Vic when the Who were hoping to incorporate live elements into Lifehouse, the other a triumphant year-end date in San Francisco -- ram home that kinetic energy in some of the best live music the band ever made. To all this, there is a Blu-ray with new Steven Wilson mixes (running the gamut of stereo, 5.1 and Atmos), various tchotchkes, and two hefty hardcover books, one documenting the creation of the album, the other a newly commissioned graphic novel of Life House (as it is called in the text and on this SDE cover). The books are handsome and the texts are informative, but the real attraction here is a deep, multi-dimensional immersion into the Who at the very peak of their creative powers. ~ Stephen Thomas Erlewine