Étude Op. 10, No. 5 in G-flat major, also known as the Black Key Étude, is a solo piano work composed by Frédéric Chopin in 1830. This work is characteristic for the arpeggios played with the right hand, almost exclusively on black keys except in measure 66, where Chopin wrote an F-natural, the only white key for the right hand throughout the entire piece.
The left hand plays the melody, with mostly chords and octaves, while the right hand accompanies with the fast triplets on black keys.
This piece is unbalanced in terms of structure, but as a romantic study, Chopin favored melodic interest over rigid structure. This étude can be divided into four parts, depending on interpretation. The first theme is introduced and expounded upon with some variation after its second repetition. The second theme is presented after two sweeping arpeggios covering half the length of the keyboard. It is short, lasting only 16 measures and is in the étude's dominant key, D-flat major. The first theme is immediately restated once, and begins developing into the coda. This development is where the only right-hand white key, F-natural, is played, in bar 66. Because this bar contains the only quarter notes in the right hand except for the last bar and it contains the previously unused F-natural, it sets up a cadence into the coda. The coda is a legato flourish in the tonic key, and ends in rapid octave passage in both hands, which is entirely staccato.
Some prominent performers, including Horowitz and Rosenthal, choose to perform the final octave passage glissando.
This étude's dynamics are more frequently notated than any other's. In the first 16 bars, Chopin indicates 14 dynamic changes, along with quick pedal fluctuations and various articulations. This does not necessarily mean dynamics should be emphasized any more than in another work, as Chopin wrote this light-hearted piece with distinct, but not heavy dynamics. These elements, coupled with the Vivace tempo, make up one of the more challenging Chopin études.