I had no idea what to expect when I went along to The Pheasantry tonight to see Bella & the Bourbon Boys perform. All I knew was that they describe themselves as a “modern jazz function band with a difference, giving a vintage twist to modern rock and pop songs”. I’d heard, also, that they write their own “jazzy covers” of pop songs, putting a retro spin on them.

That’s the beauty of Pizza Express Live, of course: it introduces you to bands and performers with whom you might not previously have been familiar. In this instance, ‘Bella’ is Amy, a South African-born jazz singer / songwriter who has performed with the likes of the KwaZulu-Natal Philharmonic Orchestra and the UCT Big Band. Shimmering in a beaded vintage dress, she was accompanied by the Bourbon Boys, a suited and booted jazz quartet.

Getting the evening underway the band’s manager and pianist Mike, told us “We’re going to turn everything you thought you knew about popular music on its head”. And they certainly did that, beginning with a languid version of ‘Valerie’ and performing Sam Smith’s ‘You’re Not the Only One’ in a 1920s style, which worked: I loved the heartwarming combination of double bass, trumpet and saxophone.

‘I Will Survive’ performed in the style of a samba was an equally pleasant surprise, as was the Arctic Monkeys’ ‘I Bet You Look Good on the Dancefloor’ – and, impressively, Katy Perry’s ‘Roar’; I dislike the original, but loved the spin that Bella & the Bourbon Boys put on it.

Guest vocalist Rebecca Harrison performed a spine-tingling version of ‘Shake It Off’ that was well-matched by Amy’s own arrangement of ‘Titanium’ – accompanied just by the piano and the double bass. Pleading, jazzy and honest, it perfectly suited her voice – as did the “New Orleansy, shuffly” version of ‘Livin’ on a Prayer’ with which the band closed their first set. Fret not, Bon Jovi fans: it was brilliant.

The second set brought forth more fun surprises, including ‘Crazy in Love’ – although I could’ve done without ‘Barbie Girl’: no jazz licks in the world could improve that song, as far as I’m concerned. But I enjoyed Jimmy McHughes’ ‘Exactly Like You’, which gave Mike the chance to show off his phenomenal skills as a pianist, and the husky, pensive ‘Georgia on my Mind’ that followed.

My kind of music – and it was evident that everyone around me felt the same: what a perfect way to spend an evening. With ‘Bad Romance’ and ‘No Diggity’ acting as a rousing encore, the audience on its feet throughout both, the night was complete.