Beethoven rewrote the overture to his only opera four times. The third version dates from the 1806 revision of Leonore, and is the longest and most symphonic of them — a slow introduction quoting Florestan's dungeon aria, an offstage trumpet call answering the arrival of the minister, and a coda of released energy. Its very completeness pushed it out of the theatre: by 1814 Beethoven had replaced it with the lighter Fidelio overture. It survives instead as a concert piece, and, in a tradition begun by Mahler, as an interlude before the final scene.