Whoever you are who periodically asks me these song title questions, keep it up. I dig it.
Cool little song by Barry Mann from 1961, asking who did all that weird doo-wop stuff back in the day and why.
I'm just going to skip right to the joke.
I put the ram in the rama lama ding your mom.
Big exhale. Feeling better. Couldn't focus. Had to get it out.
Now that I have, I don't really care to continue. I've had my fun.
Short Answer: If you sing the joke line, you have to jam 'your' and 'mom' together kinda quickly, which for me is what makes it so funny.