Ok, I translated the transcript, but I'm still a little lost in terms of why she says it. I think I understand that maybe she is wanting to add sugar to something bitter, figuratively speaking, yes?
Here is the transcript:
Sugar! Look, I was in Miami, performing at a place called Montmartre. I went to eat with my friend Raúl González. He invited Pedro, his wife, and me to a Cuban restaurant.
Well, in that restaurant, when we finished eating, as everyone does, they asked if we wanted coffee. Oh, of course, with sugar or without sugar? No, man, you know very well that you’re Cuban and know that our coffee is very bitter. I said, with sugar, and I can't take it anymore.
Sugar! And every day Celia tells the story, the sugar story, and I keep on telling the story about the Cuban, and I don’t know what, until one day I got tired and said, this story isn’t even funny anymore. The dressing rooms were upstairs, and that day they gave me the microphone up there so that I could, I travel down singing "Your Voice," and then I said "sugar," and the Cab fell down below, and I kept singing my song.