How long has it been since Rory Emerald brightened us with a blood-curdling scream?

The last time Rory Emerald performed a blood curdling scream was on the Who song 'Wont Get Fooled Again' in 1971. At the time he was working in england and was called in to dub the scream on the album Who's Next after Roger Daltry's efforts were considered too anaemic. He later taught Daltry how to perform it so he could reproduce the scream on live shows and subsequent recordings.