By 1987, Prince had already lapped his contemporaries twice. Purple Rain made him a movie star; Under the Cherry Moon flopped anyway; Kiss went to number one regardless. The pattern was clear: Prince's commercial and creative momentum were running on separate tracks, and he was flooring both simultaneously. Sign o' the Times is what happens when an artist operating at that velocity refuses to slow down for the audience, the label, or the laws of genre. The record almost didn't exist in its current form. Prince wanted a triple album. His label said no. What survived the compression — 80 minutes across two LPs — still spans Christian rock (The Cross), jazz-chord pop (Starfish and Coffee), the Fairlight CMI sampling the Aids epidemic and nuclear dread into an uneasy funk groove (the title track), and what John McKie argues is the greatest song Prince ever wrote (If I Was Your Girlfriend). The sequence isn't sequenced so much as detonated. McKie's book, built from interviews with over 100 people in Prince's orbit, illuminates the paradox at the record's center: the same man who was dating multiple women simultaneously and recording stylistically opposite songs on the same day was also, on Forever in My Life, quietly auditing his own desire to settle down. The breakup with Susannah Melvoin — his fiancée, briefly a Revolution vocalist — saturates the album's emotional register. Adore and Strange Relationship read differently once you know they're addressed to the same person. McKie's phrase is clean: 'the one that got away.' The production choices hold up under scrutiny in a way that most 1980s records do not. The Linn LM-1 drum machine gives Housequake a kick drum Prince allegedly called the greatest ever recorded. The Ballad of Dorothy Parker has muted high frequencies because engineer Susan Rogers made a mistake on a new mixing console — Prince kept it, because he believed errors were structural. McKie draws the Miles Davis comparison explicitly: Davis would call for a wrong note to be played again if it opened something new. Prince, who briefly collaborated with Davis that same year, operated from the same improvisatory philosophy, even in the studio. The difficulty of writing about Prince is that the primary source is unreliable by design. He rarely gave interviews. He kept collaborators compartmentalized. He told a journalist who wanted to understand him: 'Listen to my music.' McKie's solution — 100-plus interviews, close listening, and the acknowledgment that 'Prince was a very good poker player' — is the right one, and it produces a portrait of an artist whose opacity was not mystique for mystique's sake but a genuine cognitive architecture. He didn't share the plan because there wasn't one. There was just the next song. Six years after his death, Sign o' the Times remains the hardest Prince album to make a case against. The obvious moves — his mastery of funk, his falsetto, his guitar — are all present. But so is everything else: the social observation, the theology, the carnality, the comedy, the grief. Keith Richards once called Mick Jagger 'a nice bunch of guys.' McKie applies the formulation to Prince without the sarcasm: Sign o' the Times is a nice bunch of Princes. That's not a weakness. It's the whole argument.