At Fillmore East was recorded over two nights -- March 12 and 13, 1971 -- for which the band was paid $1250 each show. The shows were typical performances for the band, and regarded as slightly above average by drummer Jai Johanny Johanson. Ads for the shows read: "Bill Graham Presents in New York -- Johnny Winter And, Elvin Bishop Group, Extra Added Attraction: Allman Brothers." While Winter was billed as headliner, by the third night the Allman Brothers were closing the show.  Tom Dowd produced At Fillmore East; he had previously worked on their second studio album, Idlewild South. He had recently returned from Africa from working on the film Soul to Soul, and stayed in New York several days to oversee the live recording. "It was a good truck, with a 16-track machine and a great, tough-as-nails staff who took care of business," recalled Dowd. He gave the staff suggestions and noted the band had two lead guitarists and two drummers, "which was unusual, and it took some foresight to properly capture the dynamics." Things went smoothly until the band unexpectedly brought out saxophonist Rudolph "Juicy" Carter, an unknown horn player, and longstanding "unofficial" band member Thom Doucette on harmonica. "I was just hoping we could isolate them, so we could wipe them and use the songs, but they started playing and the horns were leaking all over everything, rendering the songs unusable," said Dowd. He rushed to Duane during the break to tell him to cut the horn players; while Duane loved the players, he put up no fight with Dowd. The final show was delayed because of a bomb scare, and did not end until 6 am.  Each night following the shows, the musicians and Dowd would "grab some beers and sandwiches" and head to Manhattan's Atlantic Studios to go over the performances. Set lists for following shows were crafted by listening to the recordings and going over what they could keep and what they would need to capture once more. "We wanted to give ourselves plenty of times to do it because we didn't want to go back and overdub anything, because then it wouldn't have been a real live album," said Gregg Allman, and in the end, the band only edited out Doucette's harmonica when it didn't fit. "That was our pinnacle," said Dickey Betts later. "The Fillmore days are definitely the most cherished memories that I have. If you asked everybody in the band, they would probably say that."  On June 27, the Fillmore East closed, and the band were invited to play a final, invitation-only concert, along with Edgar Winter, the Beach Boys and Country Joe McDonald. The Beach Boys initially refused to perform unless they headlined the event, but Graham refused, telling them that the Allman Brothers would be closing the show, and they were free to leave if they disagreed. The Allman Brothers' performance was used for additional tracks when an expanded version of At Fillmore East, The Fillmore Concerts, was reissued on CD.

Answer this question "what happened then?" by extracting the answer from the text above.
but they started playing and the horns were leaking all over everything, rendering the songs unusable,"