Cue the saviour in the form of Brian Kato's restoration program. You just run it and it finds the file you lost and you get it back. Simple. It does exactly what it promises to.
I have my recording back. I didn't just forget about it and give up. So that's good.
Admittedly, my case was one which might enable the most chance of recovery, given that it was a disk that is only written to when I'm changing files and I hadn't added anything else to it. A system hard disk is changing all the time and every second you leave it running makes it more likely to end up recycling the file you just lost. The above program is small enough to be run off a floppy or memory stick, so at the very least, you could try using it.
I don't feel as much a sense of loss as I was doing.