But it would be helpful if people were more consistent in using the right prefix to their thread heading when starting a new thread. Of course after that they can drift off in all directions.

And I don't think the existing set of prefixes should be seen as set in stone. For example, I think an "events" option ("EV" maybe) would useful, and the Tech could be split in to music Tech, above the line, and computer Tech, below it. And there's no obvious prfix to use for a discussion of a song's meaning and provenance, when it's not eityher a request or an addition.

If course, the list of options shouldn't be too long, or it'd be self-defeating, but if there's no appropriate one it encourages people to dispense with using any, and that catches on. In fact it has caught on, so that most of the music threads don't have any prefixes these days.