Question about Ernie's Drumming Scenes

[GeniDude]

Does Ernie always drum live on set, or is it pre-recorded sometimes?

 

[fuzzygobo]

The first time I ever saw Ernie on drums, back in the 70's. Bert had drums set up in the living room. Bert played the bass drum (pounding out a metronomic beat, but Bert thinks he's swinging like Gene Krupa). Ernie embellishes on snare and cymbals. This was all done live.
It got so wild at the end the picture fell off the wall.
Bert: "That was cold... I mean COOL!"

The times I've seen since then, the drum tracks looked mimed.