5 is known as the "Black Key Étude" as its right-hand part is entirely on black keys, except for one note. Leichtentritt states that the melodic character resulting from the use of black keys is "based on the pentatonic scale to which the piece owes its strangely playful, attractively primitive tint."
The fifth musical key, known as the "Black Key Étude," is characterized by its right-hand part being composed entirely of black keys except for one note. Leichtentritt attributes this unique melodic character to the piece's reliance on the pentatonic scale, which gives it a playful and primitive feel.