but even in the golden age of the late seventies, a lot of them fell flat.

is that it's performed live with no editing or second takes. The sketches that bombed for Monty Python, SCTV, Mad TV ended up on the cutting room floor.

It's in the writing of the sketches and the conception of characters. I find SNL sketches frequently go on too long and their recurring characters are milked far beyond when they stop being clever and funny. Contrast that with Mad TV's Stuart character, which started out as a one note joke, but as the years went on added layers of complexity to keep it fresh. I never saw a Stuart sketch that I thought didn't work for me, and that is my highest possible praise.

But Pharell Williams performed. I had heard of him before but not seen him. I was very impressed.