Gwen Stefani has released her first new music in four years.

The 51-year-old singer has gone back to her ska and reggae roots in homage to her time as the frontwoman of No Doubt and freshened things up a bit on her new single, 'Let Me Reintroduce Myself'.

In a nod to her 2004 hit 'Hollaback Girl', she sings: "And it tastes great, I already gave you bananas."

In a press release, Gwen said of the track: “This song is a way of saying I’m back with new music. It’s a fun, light-hearted song, because I got inspired and hopefully to bring a little bit of joy. The idea was to write a song that had a bit of a nostalgic feeling to it, so I think musically it reminds you of back in the day, going back to where I started musically which was with ska and reggae. I’m still the same me but heer’s something a little bit new in case you feel like hearing a little bit more of me."

Gwen's last full-length release was 2017's festive LP, 'You Make It Feel Like Christmas’.

But the new song marks her first non-Christmassy record since 2016's 'This Is What The Truth Feels Like’.

And although she never intended to make a comeback, the 'Sweet Escape' singer - who is engaged to country star Blake Shelton - has penned around "20 songs".

She told Zane Lowe on Apple Music: "I fantasized about it but I was also like ... I don't know.

I always think about artists that I loved growing up, and I think I just want to listen to the songs that I like that they did. And that's nostalgic for me."

She added: "I never expected to be writing, but it was in there. And it's been really, really incredible.

"I mean, there's just nothing else that I do in my life, and I have done so many things, that makes me feel ignited the way a new song makes me feel."

Gwen teased the song last week, tweeting: "i’ve got a new song. i want to play it for u. when are u guys gonna be around? gx (sic)"