Peter Capaldi had an idea for a musical Doctor Who episode that never got made

“I always wanted a story where he met Jimi Hendrix,” Capaldi told the crowd, “and said, ‘Jimi, your sound’s good, but…what you really need is a sort of wah-wah sound.’

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“'Let me work on that, I think I can figure out a box.’ I’ll find a little thing here, and some valves, and an old bit of shoe, in some shoe box thing, and say to Jimi, ‘Here’s a wah-wah pedal.’”

In other words, it would be a bit like that scene in Back to the Future when Marty McFly inspires Chuck Berry's future sound - but with something of a sci-fi twist.

Warming to his theme, Capaldi continued: “And of course there would have been aliens channelling themselves through Jimi’s music, to try and capture the brains of the adult population of the UK at the time.”

Sadly, though, the episode never came to pass – though some of Capaldi’s other musical suggestions were included in the series, most notably the idea that the Twelfth Doctor take up the electric guitar from the 2015 series onwards.

“I thought it would be funny if he could play the guitar, sort of like a teenager?” Capaldi told the crowd. “You know, a guitar that he’d made himself, an amp that it looked like he’d made himself.

“I thought [the Doctor] should play really badly. And I thought it’d be great if he plugged it into the Tardis control panel. That would have been great.

“I never thought they’d take it seriously, but [showrunner Steven Moffat] did! And somehow I was amazed to read this thing of me arriving on a tank playing the Tardis.”

“And of course because I am so clever and so instinctively right about these things,” Capaldi added wryly, “I said to Steven, ‘We can’t do that. That is so wrong, that will not work, it makes me look like Cher.’ But then she had a great hit with If I Could Turn Back Time, so…”

As of yet, we have no word on whether the Thirteenth Doctor will continue her predecessor’s love of musical performance, but we hold out hope. Specifically, we can’t help but feel Jodie Whittaker would look great with a massive accordion.

Doctor Who returns to BBC1 this autumn