Cerys left Catatonia in September 2001

The collaboration marks a return to high-profile mainstream performances since Matthews announced she was leaving Catatonia in September 2001.

After the split, she spent time in a clinic to sort out health problems.

She has performed at the BBC Radio 2 Folk Awards and at a St David's Day musical celebration and is reported to still be considering the direction which she wants to pursue in her career.

Organisers of the concert are not sure how the collaboration between Cerys and Cynon Valley band The Stereophonics will work, but it is expected to be unique.

"The idea is simple," said Radio 1 reporter Danny O'Connor, who has worked with V2 Records boss David Steele to organise the concert.

"Take a host of artists you wouldn't dream of putting in a small club, and ask them to do stuff that you wouldn't dream of asking them, and create a total one-off," he added.

New beginning

Music industry figure Scott Piering died from cancer in 2000.

In his career, he headed a TV and radio promotion company and helped acts including The Smiths, New Order and Prodigy.

"Scott was full of music, dry wit and laughter. This is a great way of raising a glass to him," said Mr O'Connor.

The gig, in aid of Marie Curie Cancer Care, will be held at the Scala venue in London's King's Cross on April 18.

In January, it emerged that the remaining members of Catatonia could reform under a new name.

Drummer Aled Richards revealed the band were back in the studio and were looking to secure a record deal.

With Matthews at the microphone, Catatonia released four albums and had a string of singles hits in the 1990s.