The latest tour of folk-rockers Steeleye Span is being billed as a reunion tour, but to the band it must sometimes seem like they haven't been off the road in 33 years.

Formed in 1969, Steeleye Span have been one of the most influential names in British roots music. Their early years were dogged by battles with the folk set, who wanted to keep their music pure as the driven snow, and those who wanted to stay true to its roots while reinterpreting it as they went along.

They've been through quite a few members too, but the current line-up of vocalist Maddy Prior, pictured, fiddler Peter Knight, bassist Rick Kemp and drummer Liam Genocky has some claim to being a classic - even though all four haven't shared the same stage for 16 years.

Maddy Prior, who's been singing with the band for 28 of their 33 years, said: "Steeleye Span is like a bus. It goes along, and people get on and get off it.

"Sometimes the bus goes along the route you want to go, and sometimes it turns off, so you get off.

"People do seem to come in and out of Steeleye. There's been a few people who've been in, gone out, come back in.

"We don't ever actually have a plan. Whatever the material does, that's where we go. We have an arrangement, but even that gets adapted.

"But, of course, sometimes everybody's got a really clear idea of what's going on!"

The band have already proved their enduring popularity by selling out their Sunday evening date - so they promptly added another the day after.

Tickets for the 7.30pm show at Abergavenny's Borough Theatre, which coincides with the release of The Very Best of Steeleye Span, are £15 or £13.50 concessions. Box office 01873 850805.