Currently, `emms-single-track' is a buffer-local variable; it will only apply to the playlist in which it is set.
In contrast, `emms-repeat-track' will apply to all playlists if set. I think that `emms-repeat-track' should be buffer-local as well. But I will defer changing it for a while (a couple of weeks) to allow people to write in with different opinions, on the off-chance that someone has a different use case that makes setting `emms-repeat-track' everywhere annoying. -- "Cut your own wood and it will warm you twice"
