The Allman Brothers Band

Question: According to Willie Perkin’s book on the Allmans, it seems the band played with the horns on the 12th, and without the horns on the 13th. It makes more sense that they played with the horns on the 11th, and without on the 12 and 13th, as you indicate. If Perkins is correct, then Fillmore East was recorded all on the 13th, in one night?

Can anyone confirm? I’d appreciate it.
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