Beethoven wrote four overtures for his only opera, Fidelio; three "Leonore" overtures, each numbered; and one called Overture to Fidelio. It has been common practice to use the latter as a prelude to the opera in productions of Fidelio. The Leonore No. 1 was withdrawn by the finicky Beethoven and not heard until 1828, the year after his death. That circumstance explains its high opus number and the fact that the Overture is generally heard as an independent concert work today, apart from productions of the opera.
The Leonore Overture No. 1 opens somberly, the strings rising slowly from their lower ranges, finally finding brighter territory, as woodwinds join in and the pacing becomes a bit livelier. Still, the mood remains unsettled, with a sense of probing, of uncertainty. Soon, however, the tempo turns animated and the music brightens, a sense of joy and hope emerging in the lively, muscular theme. Another slow section ensues, but here the music quickly casts off the sense of doubt that reemerges and develops an epic character with a soaring, heroic theme. The triumphant, joyful closing episode builds upon this all-conquering feeling to banish all sense of doubt. Throughout this approximately ten-minute Overture, the music comes across as a deft admixture of the serious and light in its colorful but necessarily cursory summation of the opera's story about the faithful and persistent Leonora, disguised as the young man Fidelio, to free her husband Florestan from the prison of the evil Pizzaro.