Recent years have seen the rise of the term "intelligent dance music," a phrase used to describe dance music consumed by those generally ashamed of the genre. It's too bad no one thought it up in time to apply it to the music of Pet Shop Boys, Neil Tennant and Chris Lowe's venerable two-man dance band. They would have loved sneering at it. Lowe and Tennant have always worn their brains on their sleeves, but they've also made a career out of unapologetically embracing the most intellectually suspect dance music around: disco. Finding no contradiction among cleverness, inventive songwriting, and a thumping beat, Lowe and Tennant have been as in touch with their times as any great team of the past, as a hefty stack of recently reissued albums generally confirms. Their talents, though later refined, were apparent from the start. There may be no better commentary on the Reagan/Thatcher '80s than "Opportunities," a wry, unforgettable sketch of crime, sex, and technology in conspiracy, from Pet Shop Boys' 1986 debut Please. Later albums practiced a greater consistency, but PSB's early work offered no shortage of high points: A decent greatest-hits album could be constructed just from the singles of Please and its 1987 follow-up Actually. Reversing most dance bands' habit of producing albums of singles-length material, supplemented by extended-mix singles, 1988's Introspective offered a mere six songs stretched to floor-packing length. The experiment worked fine, but hardly suggested the twin peaks of 1990's Behaviour and 1993's Very, two sharply contrasting albums that now look like the duo's best work to date. Capturing a culture devastated by AIDS, the elegiac "Being Boring" sets the tone of the melancholy Behaviour, an album of heartbreak in which political and romantic collapse find equal space for expression. Almost by way of an unneeded apology, Very keeps the mood bright even when its lyrics suggest that all is not well. It concludes with a gesture that only Tennant and Lowe could pull off, a reworking of The Village People's "Go West" in the style of an anthem for an imagined gay utopia; the song dares listeners to dismiss it as simple irony. Like most dance acts, Pet Shop Boys is only partially represented by its albums; in their new incarnations, the group's first five records (stretching out to a sixth, Bilingual, for British consumers) come supplemented by a second disc of remixes and album-worthy B-sides, as well as booklets with wry, insightful, track-by-track commentary from Tennant and Lowe (mostly Tennant). The series essentially sets a new gold standard for CD reissues, and its subject deserves no less.