The musical began life on the West End in the early 1960s and had a couple of oddities about it. First, the show brought its star to eventual international fame. Tommy Steele had been a very popular rock star, though pretty much known only in England. He'd made some movies, but going on stage in Half a Sixpence was a big leap for him, and then he transferred with the show to Broadway, where it again was a big hit, and later starred in the movie version. The other oddity is that the musical comedy is based on a novel by, of all people, H.G. Wells, titled Kipps.
The show got revived last year at the Chichester Festival and then moved to London where it had a scheduled 10-month run, set to close last month. They didn't just re-stage the musical, though but brought in Julian Fellowes (of Downton Abbey) to rework the show's book, and had two songwriters -- George Stiles for the music, with lyrics by Anthony Drewe -- to expand the score and fit Fellowes' new material. That's always a bit of a risk, blending musical styles, especially since the original score by David Heneker is extremely good.
This is one of the new songs, "Pick Out a Simple Tune," lead by the show's star, Charlie Stemp. It seems like perhaps it might replace the song "Money to Burn," in the original, where the lower-class Kipps is asked what he'll do with the big inheritance he's going to be receiving, taking him into high society -- and the best he can come up with, for some reason, is that he'd buy a banjo. (The reason for this seems to have only been to give Tommy Steele the opportunity to play the instrument on stage.) So, if this does replace that song, it's not unreasonable. In fairness, it's not all that substantive a song itself, but it has a light charm, and turns into a very enjoyable production number.
From what I've read, it's possible that a DVD of this production will be released, so fans of Half a Sixpence may have a chance to check out the new version.