Pixies lead singer Black Francis performs at the O2 Academy, Brixton in London, Britain, Dec. 6, 2016.
Pixies lead singer Black Francis performs at the O2 Academy, Brixton in London, Britain, Dec. 6, 2016.

Pixies frontman Black Francis has been called many things in his time - surrealist poet, alt-rock progenitor and singer in "one of America's greatest bands ever," that last one according to Bono of U2.

Sitting backstage at the O2 Academy in London's Brixton before another sold-out gig, the singer tries on yet another label for size as he discusses what drives him 30 years into a career that many argue changed the face of music.

"What motivates [us]? ... It's not about being inspired by something or being motivated by something. If you decide to become ... pardon the expression, a 'troubadour' then you become a troubadour, that's who you are," says the 51-year-old, also known as Charles Michael Kittridge Thompson IV. "Its not even like ' Do you feel like doing it today?' , It's just like - that's what I do."

The Pixies began with four albums and an EP in the late 80s and early 90s. They broke up, then after a few more serious bumps in the road, came back and kept going.

That first seven-year burst cut through the glop of 80s pop with raw screaming vocals, loud-quiet-loud dynamics and songs about lust, the bible and UFOs, among them "Debaser" and "Monkey Gone To Heaven."

Everyone from Nirvana to David Bowie queued up to pay homage. The band split in 1993 as tensions boiled over between Thompson and bass player Kim Deal, then reformed to huge acclaim in 2004.

Deal left again in 2013, leading to the Pixies' third reincarnation, possibly their most challenging yet, as a band ploughing on after the revolution it triggered had been absorbed into the mainstream.

It is a shift underlined half way through the Brixton concert, when the Pixies' new bass player Paz Lenchantin steps up to the  mic and sings "All I Think About Now," a song she wrote with Thompson, a plain-spoken tribute to Deal.

"The only reason I am here is Kim, so I thought it would be good to sing about Kim, like a thank you letter," says Lenchantin backstage. "We're kind of waiting for her [Deal's] sung response," adds Thompson, chuckling.

In an early blow, "Indie Cindy," their first album after the reunion, secured dire reviews.

But many critics have held up their current release "Head Carrier" as a return to form. And there is a new solidity about the band since Lenchantin joined full-time.

"She completes the band because without her we're just like three dudes who just used to be in a band," says Thomson. "We're a band again. We're Pixies again."