The Smashing Pumpkins’ sophomore effort, ‘Siamese Dream,’ may be second only to Nirvana’s ‘Nevermind’ on the list of most influential grunge-era albums. It is, without a doubt, one of the most important records of the ’90s, and today, it turns 20 years old.

While Nirvana is credited with booting rock's reigning hair-metal overlords through the pop-culture exit doors and reintroducing strains of punk into the mainstream, Billy Corgan’s textured, otherworldly, effects-heavy guitars -- which seem to whirl in a sonic tornado -- brought a variation of shoegaze to the mainstream. Produced by ‘Nevermind’ mastermind Butch Vig, 'Siamese Dream' is a high-water mark in recorded sound, as it emphasizes the band’s three greatest strengths: Corgan’s androgynous vocals, his highly inventive (near proggy) lead guitar work and Jimmy Chamberlin’s undisputed drumming genius. Notably, the album was mixed by Alan Moulder, who worked with another set of shoegaze gods, My Bloody Valentine, on their highly influential ‘Loveless.’

Casual fans may be surprised to learn that Corgan and Chamberlin cut 'Siamese Dream' mostly by themselves. Corgan, an art-above-all control freak you might call the David Crosby of his era, often recorded over D’arcy Wretzky and James Iha’s bass and guitar parts, though judging by the brilliant results, it's hard to fault him.

Singles abounded on 'Siamese Dream,' among them lead burner ‘Cherub Rock,’ which aptly starts the album with a drum roll; the string-laden acoustic ballad ‘Disarm’; and the wall of noise ‘Rocket.’ But the single with the most lasting effect on modern music is, without question, ‘Today,’ whose tinkling lead-guitar hook, loud-soft structure and introspective, murmured lyrics added up to a formula countless lesser bands would copy for the remainder of the decade.

'Siamese Dream' debuted at No. 10 on the Billboard 200 and has sold 6 million copies worldwide. The album routinely lands on critics' best-of lists, and in 2003, Rolling Stone ranked it No. 362 on its list of the 500 Greatest Albums of All Time. For many bands, it would mark a career pinnacle, but amazingly, the Pumpkins have fared better with each post-'Dream' album, the most successful of which, 'Mellon Collie and the Infinite Sadness,' arrived a little more than two years later.