Information about Theme Song does not exist on MDL... People are REALLY interested in all the sound tracks, usually. Questions about "which song played in episode xy, during xy minute" are endless.
But, on the contrary, MDL does not list "Music" in general info about a drama AT ALL. It lists Director, Original Network, etc... Music should also be there! After all, don't all the reviews include rating for Music?
We should have the information who did music for the drama. About the Opening Theme, Insert Theme, Closing Theme... That would be basic. And like I mentioned, people would kill for info about Featured songs sometimes;-)