To celebrate the incredibly prolific, influential and diverse body of work left behind by Prince, we will be exploring a different song of his each day for an entire year with the series 365 Prince Songs in a Year.

Prince's championing of younger artists was legendary, and one of those up-and-comers who benefited from his endorsement was Kendrick Lamar. On Sept. 30, 2014, six months before the release of Lamar's third album, To Pimp a Butterfly, the rapper was on stage with Prince at Paisley Park, freestyling over "What's My Name," a track found on 1998's three-disc compilation, Crystal Ball.

According to Prince Vault, "What's My Name" stems from mid-1993, where it was heard on the Paisley Park Hotline, a telephone service that promised to have the information on Prince's new name. However, it was launched a week after it was learned that he had changed his name to the Love Symbol.

Lyrically, his frustration at being trapped within Warner Bros. constrictions becomes a question of identity (Take my name, I don't need it / Nothing stays the same anyway / Take my fame, I can't use it / My girlfriend calls me lame, the game was over yesterday"). The track spills over into rage via the chaotic music.

The jam between Prince, 3rdeyegirl and Lamar took place at a party to celebrate the release of Prince's twin 2014 albums Art Official Age and PlectrumElectrum and was streamed at Yahoo! Three years later, Lamar was on The Howard Stern Show recalling that evening.

“It’s one of those things where, it was so much going on in the moment, man,” he said. "I didn’t even know I was coming out on stage. The studio was next door where I just played him the song. We were running back and forth."

Lamar had flown out to Minnesota to play him To Pimp a Butterfly's "Complexion (A Zulu Love)" with the hopes of getting Prince to perform the hook on it. "Prince heard the record, loved the record and the concept of the record got us to talking," Lamar told "We got to a point where we were just talking in the studio and the more time that passed we realized we weren't recording anything. We just ran out of time, it's as simple as that."

He added to Stern that having Prince listen to his track was "just one of my favorite moments." But what happened later that night was even more mind-blowing to him. He had been under the impression that he was only at Paisley Park for a meeting and, before he knew it, he was performing with him.

“He was doing an event and he’s like, 'You want to watch me on the event?' Yeah I want to watch! I’m out there watching and he says, 'Come on stage' in mid-performance. So I’m up there freestyling and it just turned into something else. I totally forgot about the song after that (laughs). ... It’s a surreal moment because this is one of the people I idolized.”

You can watch it above. For someone who didn't even expect to be onstage, Lamar picks up on the song's dynamics very quickly. After his own verse, Prince moves over to the keyboards for some funky stabs as 3rdeyegirl guitarist Donna Grantis solos over the song that preceded "What's My Name" in Crystal Ball's sequence, "Calhoun Square."