Bobby Caldwell, the blue-eyed soul singer best known for his hit single “What You Won’t Do for Love,” has died at the age of 71.

Caldwell’s wife, Mary, confirmed the singer’s death on social media on Wednesday, March 15th. TMZ reports that he had been battling an unspecified illness for several years.

As a teenager, Caldwell moved to Los Angeles to pursue a career in music. He briefly played rhythm guitar for Little Richard, but it took six years for him to catch his big break and land a recording deal with TK Records. “What You Won’t Do for Love,” appeared on his 1978 self-titled debut album, and hit the top 10 on the Billboard Hot 100. In the ensuing years, the song would be sampled by a number of hip-hop and R&B artists, including Tupac on “Do for Love.”

As TK Records mainly released records by Black artists, the label initially sought conceal that Caldwell was white by using a silhouette on the cover of his debut album. “But that was quickly laid to rest when I had my first tour which was opening for Natalie Cole… She was playing large venues, 4,500-plus. And ‘What You Won’t Do For Love’ was, at that point, working its way up, so I was very surprised at seeing nothing but black in the audience. And certainly they were probably more surprised than I was,” Caldwell recalled in a 2005 interview with NPR.

“I walked out on stage and you could hear a pin drop, just a total hush came over the crowd,” he separately told Red Bull Music Academy. “It was like, ‘What the fuck is this!?’ I stayed and delivered, after about ten minutes, I had them in my pocket. That was the night I became a man, I’ll tell ya.”

Caldwell released several more albums throughout the 1980s, including Cat in the Hat and Carry On. “Open Your Eyes,” from Cat in the Hat, was later sampled by J Dilla on Common’s “The Light,” and covered by John Legend.

Caldwell also penned the chart-topping song sung by “The Next Time I Fall” for Peter Cetera and Amy Grant. Additionally, he wrote music on behalf of Neil Diamond, Roy Ayers, Roberta Flack, and Natalie Cole.

Later in his career, Caldwell’s interest shifted to recording big band arrangements of Frank Sinatra and other music from the Great American Songbook. He also portrayed Sinatra in the Las Vegas musical The Rat Pack is Back.