When Bonnie Raitt won a phenomenal four Grammys in 1990, it came as overdue recognition for an artist who had been breaking down barriers of gender and genre since the 1970′s. As a musician, she emerged as both prodigy and anomaly: a young woman who sang blues with gritty passion and played slide guitar with authority, as if the genre’s fundaments had been etched in her soul.

Her emergence as a …