Not common perhaps but certainly tried out. We were told in the sixties that it was a speech speed, roughly comparable perhaps to 1.75 ips on tape but I never saw one then? Nonetheless slowing your LP's down to 16 helped a lot with learning Guitar "licks", not that I was much good at it
. I even had a tutorial LP where you were advised to re-play some sections at 16 instead of 33! There are lots of 16 rpm threads on here but not directly specific to Dai's question. Some address the ORIGIN of the 16 rpm speed, sometimes linking it to the film industry and the developement of optical sound. People often ask are there any records around that play at 16 rpm? Well of course, they all do
Dave