Praise's suggestion that people lamenting the lack of music threads might be because they have answers rather than the questions makes sense. Mind you, if you've got some area of interest expertise you don't have to wait for a question to make it available. There's provision in the Mudcat for articles; and a thread doesn't need to start with a question, it can start with someone expressing an opinion, for example.

I prefer thread titles that are straighforward, rather than ones that set out to be "intriguing", which doesn't normally work. But the great thing about threads is that soemthing that starts out as facetious,or offensive,or silly can turn into something interesting. It's all doiwn to us.

It helps sometimes to draw people's attention to threads where they might have useful information to give, by sending them PMs, or by sticking a link in a post where some other discussion was starting to become relevant.

That seems a better way of tapping into expertise than any formal arrangement. Imagine the potential ructions, with people resenting that they weren't officially accepted as experts, or that someone else was. Or you'd have modest people feeling reluctant to chip in with info they had, because they'd feel they weren't entitled to.