It first appeared on the Agents of Fortune album. [1976]
Prior studio recordings of it had no cowbell.
According to the book “Blue Oyster Cult: Secrets Revealed!” there was no cowbell in the original final studio version.
Sandy Pearlman, for whatever reason, later decided to add it in and Eric Bloom over-dubbed the cowbell onto the finished recording.
They still don’t use it live.
If you have the live albums BOC: Extended Versions, “On Your Feet Or On Your Knees” or “Some Enchanted Evening”, you’ll be mercifully freed from the accursed cowbell......:)
Thank goodness... I was worried that it was just in my imagination... That Christopher Walken had invaded my mind and injected me with the cure - "More Cowbell!"
Mark