Three decades ago, The Boo Radleys made a psychedelic masterpiece that was hailed by NME as one of the top albums of 1993. Their next album spawned a sunny Britpop hit and rose to No. 1 on the U.K. album charts, and the next one was rumored to have influenced Radiohead. So why is the band so overlooked today? “I think we just confused people,” says lead singer Simon “Sice” Rowbottom on the eve of the band’s first album in 23 years. Sice observes that the Boos’ willingness to transcend genre—originating as a My Bloody Valentine-inspired shoegaze outfit; melding roaring guitar with eclectic instrumentation and avant-noise psychedelia on 1993’s extraordinarily potent Giant Steps; then being labeled a Britpop act with 1995’s Wake Up!—left critics and fans unsure how to categorize the group. In...