Billy Corgan has never been a man for the easy road. Or, indeed, the normal road. In the mid-’90s, when such things were still openly laughed at as the products of self-indulgence and pretension, in a musical world where rawness and sweat had become a valued commodity, he decided that Smashing Pumpkins would release a sprawling double album, Mellon Collie And The Infinite Sadness. It was massive. Last November, 27 years after the first third of what would become a trilogy with 2000’s Machina/The Machines Of God, the band began rolling out the closing chapter. Aptly, it was a triple album, a rock opera. “About one-third of it’s heavy,” Billy told us at the time. Oh, and rather than coming in one big binge, he was going to unveil and discus...