ABBA gave the world something that the music industry spends every decade since trying to recreate and never quite managing — a sound so immediately joyful and so completely itself that it bypassed every critical defense and landed directly in the place where people keep the music that means something to them personally, the music they sing alone in the car and reach for on the worst days and associate with the best ones. Benny Andersson was half the musical engine behind all of it — the pianist and composer who sat beside

Björn Ulvaeus and built the arrangements and the harmonies and the specific sonic architecture that made Dancing Queen and The Winner Takes It All and Fernando and Waterloo and everything else feel simultaneously like pop perfection and something considerably more emotionally serious than pop perfection is supposed to be. And then in 1982 it was simply over — no farewell tour, no formal announcement, no careful managed goodbye, just a silence that descended on one of the most successful musical acts in history and that the millions of fans who loved them spent the better part of four decades trying to fully understand. The official explanations — the marriages ending, the personal toll, the natural conclusion of a creative partnership — were accurate as far as they went and never quite went far enough, leaving the full truth of why ABBA vanished at exactly the moment it did in the particular unresolved space that only the people who were actually inside it could fully map. At 78, with the distance of forty years and the perspective that only comes from a life lived completely enough to understand which truths still need telling, Benny Andersson has finally said what he was not prepared to say before — and the fans who have been waiting, in some cases literally their entire lives, for the complete answer to the question that The Day Before You Came seemed to be asking were not remotely prepared for what it turned out to be.