Here's a clip from a documentary in which the musician recalls an appearance on The Old Grey Whistle Test, followed by a rendition of "May I?" by his incredible Whole World band, which at the time featured Lol Coxhill and Mike Oldfield. My first exposure to the tune was a somewhat more raucous rendition from the legendary concert album June 1, 1974.
The obituary from Mojo is worth a read. I haven't much to say at the moment except that Ayer's music meant a lot to me growing up, and continues to.