Gwen Stefani recently revealed that she received songwriting tips from Prince and Idolator reports that she returned the favor by joining the Purple One on stage on Saturday, April 30 at The Forum, which is part of the enigmatic singer’s 21-night residency in LA, the dates of which he is announcing in piecemeal fashion!

Fans that attended the April 30 show were treated to Stefani sauntering on stage to perform 'So Far, So Pleased' with Prince. The crowd was incredibly pleased at this bonus performance, which was essentially the collision of two pop idols on a single stage. Of course, Stefani, who attended the show with husband Gavin Rossdale of Bush, looked as radiant and fashion-forward as ever in a white polka dot romper ensemble with black stockings.

Prince and Stefani go way back. They recorded the song 'Waiting Room' for her band No Doubt's last album, 2001's 'Rock Steady.' Stefani also revealed Prince's advice in her candid chat in ELLE's May issue, saying, "Prince, who is one of my idols, gave me some advice when I worked with him: 'Have you ever just tried writing a hit? Like, don't just try writing a song, try and write a hit song.' I remember him saying that and me thinking, 'Yeah, you're right. Why would you write anything else?'" Sound advice, indeed.

Watch Gwen Stefani Get Her Groove on With Prince!