There are albums that are so deeply etched into the collective memory that even hearing a single riff is enough to instantly identify them. “Aqualung” is one of them. Jethro Tull’s fourth studio album, released in 1971, marked the band’s international breakthrough and remains to this day a staple of the progressive rock canon, known far beyond the boundaries of the genre.

The album thrives on its contrasts: harder rock songs meet acoustic, almost chamber-music-like passages. Ian Anderson’s flute serves as the lead instrument alongside distorted guitar; Martin Barre’s powerful playing contrasts with moments of silence; and John Evans’s organ acts as a tonal link. The tracks range from the raw immediacy of the title track to the driving energy of “Locomotive Breath” and the fragile intimacy of “Wond’ring Aloud.” The album is often described as conceptual, driven by a critical examination of organized religion—a characterization the band has consistently refuted, and which, for that very reason, remains part of the discussion to this day.

Steven Wilson was responsible for the Dolby Atmos mix. Especially for an album that relies so heavily on the contrast between loud and soft moments, the spatial separation of these layers is the obvious benefit: where acoustic and electric elements, vocals, and instruments are tightly packed together in the original, the immersive mix gives them their own space. For *Aqualung*, this is also the first time the Atmos mix has been released on a physical medium. The set is rounded out by a remastered 5.1 mix, stereo and instrumental versions, as well as the original 1974 quadraphonic mix, which holds its own unique appeal as a historical document. In addition, there are outtakes and early versions from the original sessions, including early takes of “Aqualung” and “Locomotive Breath,” which show how the songs gradually evolved toward their final sound.