Here's an obscure Filmation cartoon that aired on ABC from 1969 to 1971 based (rather loosely) on the Hardy Boys books. It's never been *officially* released on DVD or VHS, although 2 DVD's (one with 5 episodes, and another with 10) have popped up at toy conventions and online. Seems like this would make an interesting preservation project
The basic premise of the show turned the Hardy Boys into a rock band, which is used as a front to investigate crimes. The group consisted of Joe and Frank Hardy (Joe being the blond/brown haired one, Frank being the black haired guy), Pete Jones (the African American), Chet ("Chubby") Morton (guess), and Wanda-Kay (once again, take a wild guess). The show is notable for being the first cartoon to ever feature a regular Black character, but other than that it's just the bastard child of "Scooby Doo" (which ran in the same timeslot) and "The Archie Show". Each episode consisted of two mysteries based on the books, plus a music video that played in between.
View at your own risk. The "Mourning" part of the thread title isn't a typo
http://www.youtube.com/watch?v=GNS6HhtElLo (intro)
http://www.youtube.com/watch?v=CfJrB7IQmnM (a music video that played between the two mysteries)
http://www.youtube.com/watch?v=bA0mkvmEHsA (a clip of an episode as well as the outro)