I have to plead guilty to doing the same as Jeri. If we see a new thread starting, we often move the new messages to an older thread on the same subject, thereby eliminating duplication and those nagging messages telling people to "use the search box first." It usually seems best to keep all the information on a subject in a single thread, or in as few threads as possible.
For songs, I try to move the most informative messages into a single thread, and mark that thread as an "origins" thread if it truly does give good information on the background of a song.
-Joe-