Music legends, unite! Insiders are buzzing that the longtime friendship between Mariah Carey and Lenny Kravitz has evolved into something more. “There’s definitely chemistry between them,” says a source. “They’re both single and they’ve been hanging out a lot lately.”

Mariah, 55, and Lenny, 59, were pals long before they achieved fame. As the “Fly Away” singer recently revealed, he used to frequent the New York City sports bar where Mariah worked when they were both aspiring musicians comparing demo tapes. They’ve crossed paths many times since, costarring in 2009’s Precious and more recently, attending February’s Recording Academy Honors where they each collected an award. They also just received simultaneous nominations for the Rock ’n’ Roll Hall of Fame.

“They bonded over both being nominated,” says the source, who adds that Lenny has “always admired Mariah,” and developed a crush on the Precious set. (She was married to Nick Cannon at the time; he split from Lisa Bonet in 1993 and later dated French actress Vanessa Paradis).

“They’ve been super close over the years, and they have a lot in common so it’s not surprising that they could have taken their friendship to the next level,” spills the source, adding, “Everyone who knows them personally in the music industry is buzzing about it — and wants it to be true!”