Themeweavers, LLC does the opening music (the song that is then used as bed music)-- but I don't remember who does the "People's Theme."
edit: And I don't have time now, but if you copy the whole text of the archive page and paste it into Numbers or Excel, it will give each line its own numbered row. You can then delete the superfluous rows, and then you'd delete the ones where other DJs filled and, and then listen to the archive for the older shows that have no description to see if they were really Best Shows or not. That's the only way I could think to get the number of shows easily.