I just said I agreed entirely with Glyn, but - sorry, Glyn - I wonder whether actually it does have to be BBC quality. At least, it needs to be of a highly professional standard, same as the cover, same as the work itself.
https://www.audacityteam.org/ (NB: With one slip of the mouse, I up-voted myself on the previous post. What a numpty. There doesn't seem to be a way of removing it.)
That was what I was trying to say - it doesn't have to be BBC quality. It takes a finely tuned ear and the best playback system to spot the difference between good amateur/semipro and B B C.