Though I don't get why the prologue's tempo is so fast. I wonder if that was really the tempo on opening night? Or did something happen to the file over the years? Remember that these "files" weren't "files"--they were tape--until the early or mid 1990s, when floppy discs and analog-to-digital converters came into commons use. So for 20 years they were floating around and dubbed, machine-to-machine, and stored in less-than-archival conditions.
Tape stretches, It breaks. It expands in heat and contracts in cold. It plays at different speeds on different players. And the people who were duplicating the tapes were not doing it in the open. They were doing it in secret, legitimately afraid of "getting busted," the same way they were secretive about gay sex and drug use.
Look at the way I was freaked out about the "Follies in Miniature" when I first joined BWW. I had hoarded it for 15 years, dubbing the 3rd-generation videotape as birthday and Christmas gifts for those I thought I could trust. Now it's a Megaupload/Megavideo link, which I give to anyone who is interested.
Personally, I can't listen to those soundboards of Follies. I make allowances for the crappy videos because they're the only visual record of this visually remarkable production. But the soundboard audios are like nails on chalkboard to me.
As far as I can tell the entire August 2, 1971 soundboard is too fast. The prologue is too fast, the voices are higher pitched than they were onstage (or are on the OBCR) and all the intros to the songs are way too fast.
And that LA soundboard is the opposite: it's too slow!