It’s been over 20 years since Nonesuch Records came out “The John Adams Ear Box” a 10-disc retrospective of the Berkeley composer’s work. At the time, the collection was authoritative, a definitive account of one of the most important achievements of American classical music of the late 20th century.

Turns out that was just the beginning.

As the musical world eagerly awaits Adams’ next big reveal – the September 10 premiere of his new opera, “Antony and Cleopatra,” commissioned to celebrate the San Francisco Opera’s centennial – Nonesuch has posted a visit even more complete. for the remarkable arc of this composer’s career. “John Adams: Collected Works,” a massive 40-disc box set, includes just about everything important, from proto-minimalist forays of the 1970s and early 80s to the thunderous explosions of the magnificent 2018 piano concerto from Adams “Must the devil have all the right tunes?”

Taken together, the set does everything an insight into a creative career should. It illuminates both the stylistic premises and the specific artistic choices Adams has adopted over nearly half a century of dedicated creative endeavour. It charts a compelling chronological narrative, as Adams discovers a distinctive musical voice and then pursues it in a myriad of diverse but fundamentally related directions.

But most basic, the set provides massive amounts of damn fine listening. It’s hours of exciting, beautiful, inventive, funny and breathtakingly original music – sometimes in succession, sometimes all at once. It will leave you with melodies and entire musical episodes bouncing around in your head for days.

To some extent, all of this was already in place in 1999’s “Earbox,” which documented Adams’ career up to the turn of the millennium. Many of those early recordings are back to serve as the basis for the new ensemble, including the choral masterpiece “Harmonium,” Walt Whitman’s gloriously tender setting “The Dresser” (expressly sung by the late baritone Sanford Sylvan) and the still underrated 1991 symphonic poem “El Dorado”.

But even some of those offerings have returned in expanded form. Adams’ first two operas, ‘Nixon in China’ and ‘The Death of Klinghoffer’, plus the hard-to-classify pop-tinged ‘song-play’ titled ‘I Looked at the Ceiling and Then I Saw the Sky’ , were both originally represented by snippets. Now they’re presented in their entirety – not just with audio, but in the case of “Nixon” with a 2011 Metropolitan Opera Blu-ray video presentation.

On top of that comes a jumble of substantial pieces – both big and small, but mostly big – from Adams’ last two decades. The Opera “Atomic Doctor” is here in its entirety, together with the symphony derived from its thematic material. The same goes for “On the Transmigration of Souls,” the 9/11 memorial for which Adams won the Pulitzer Prize for Music 2003.

There are the not exactly operatic stage works, “El Niño”, “A Flowering Tree” and “The Gospel According to the Other Mary.” There are concertos for violin, piano, saxophone and string quartet, and the continuing fruit of Adams’ characteristic formal innovation, the three-movement orchestral symphonic poem (illustrated, among other things, by the richly imagined “Naïve and Sentimental Music”).

The set even includes recordings of Adams conducting the music of other composers, including Charles Ives, Morton Feldman and the late Ingram Marshall.

Not included, for better or worse, was Adams’ earlier opera, “Girls of the Golden West,” which hit at least one listener like an artistic dud of epic proportions. Perhaps the context of the composer’s entire catalog would have given the score a different twist.

In any case, the whole thing bristles with discoveries and rediscoveries, old truths confirmed and new ones unveiled.

One of the main takeaways – not a new idea, but one that keeps taking on added dimensions – is how central the orchestra is to Adams’ imagination and how skillfully he deploys it. . Almost everything he wrote appears in a vibrant web of instrumental color, using the traditional orchestral scale and complementing it with inventive ringtones such as the cimbalom, a hammered dulcimer.

A related aspect is the consistency with which Adams operates on the broadest of formal canvases. The catalog of almost every other great composer, past or present, is dotted with small one-off works – a chamber piece, a piano sonata, a fanfare written for a special occasion. Adams has a few in the lineup, but they don’t feature very prominently; he’s always more interested in taking the big home run.

The grand program he has in mind is often stylistic. It is reductive but fundamentally accurate to say that Adams found his mature compositional voice with the 1985 orchestral work “Harmonielehre,” who forged a personal and wholly original fusion between the minimalism of Philip Glass and Steve Reich and the late romantic language of Sibelius and Wagner.

“Harmonielehre” is still the purest embodiment of this stylistic hybrid and the single work that best encapsulates Adams’ legacy. It is no coincidence that the piece comes both first and last in this collection, which begins with the original 1985 recording by Edo de Waart and the San Francisco Symphony Orchestra, and ends by a somewhat livelier account from 2016 by Adams and the Berlin Philharmonic Orchestra.

But Adams’ language also becomes omnivorous in other directions, including jazz. For me, the clearest revelation here was the combination of “City Noir” – a dynamic big band pastiche that never really made sense before – and the Saxophone Concerto, with the tireless solo work of Timothy McAllister. It’s also remarkable to hear Adams develop an idiosyncratically maximalist approach to the concerto over the decades.

And more, and more, and more. There are hours of fun and awe to be had here – perhaps just enough to keep us going until ‘Antony and Cleopatra’ arrives.

John Adams: Collected Works: Nonesuch (40 discs). $172.