I always thought about that too after watching the documentary 30 thousand times ( about why the other members weren't mentioned ) I think Lee really missed them as it shows when hes talking about petes circle and seasons album and hears fred and ronnie on the last track he gets kind of emoitional. I dont think Erik was doing the music thing at that time. Personally I think that Lee wanted the orginal four to preform one last time together and to hang out one last time because he knew his time was coming. Of course I cant speak for the guy but thats what I think anyways. Im not sure what Frank or Bernie or Erik werent credited it at all I know lee wrote the script for the movie though