The TV choir master will be appearing at Latitude 2015 this summer and ticket holders are being urged to apply for his 100-strong group.
Following a rehearsal with Gareth, successful festival-goers will take to the Main Stage and perform during a lunch time slot.
Considering Noel Gallagher and The Vaccines are also on the bill, it seems like a pretty cool opportunity to us!
The festival takes place in Southwold, Suffolk, on 16 to 19 July and will also feature comedy performances from Jason Manford, Alan Davies and Jon Richardson.
Gareth and his Voices choir will be performing at the event and, announcing his exciting news on Twitter today, the musician said: "If you are thinking of joining us at Latitude, there's a chance to sing in a special choir with Voices and me...."
Last year, Gareth knocked Cheryl Fernandez-Versini off the top of the charts with his All Star Choir, which he put together for Children in Need.
Celebrities including Gavin & Stacey's Alison Steadman and Larry Lamb were among the group, along with Great British Bake Off host Mel Giedroyc, and they recorded a cover of Avicii's hit 'Wake Me Up'.
Gareth is also the man behind the hugely successful Military Wives Choir.
For Latitude 2015 tickets, click here!
Watch Gareth's All Star Choir video for 'Wake Me Up' here: