‘Awoman who was in a relationship with Prince years ago told me that when he gave women baths he took total control.” This nugget exemplifies what’s engaging about “I Would Die 4 U,” Touré’s study of the protean pop star’s meaning and appeal. It’s gossipy and a little prurient; it’s also enlightening if you’re among the millions who absorbed Prince’s music like an intravenous infusion, especially at his mid-1980s zenith.

 If you’re one of those — one of us — then you’ll make immediate connections: to the washing fantasy in “If I Was Your Girlfriend” and the two baths taken in “The Ballad of Dorothy Parker,” on the 1987 double album “Sign ‘O’ the Times,” or to Wendy and Lisa in “Computer Blue’’ on “Purple Rain” (“Is the water warm enough?” “Yes, Lisa.”). You can then follow Touré as he relates Prince’s penchant for bathing women to the artist’s childhood, family drama, gendered self-identification, and religious inclinations. (Think baptism and immersion.)