D♯, or D sharp, is a musical note that is one semitone higher than D and one semitone lower than E. It is commonly used in various musical scales and compositions, particularly in genres like classical, jazz, and pop. In the context of a piano, D♯ is played by pressing the black key immediately to the right of D. In music theory, D♯ can be represented as an enharmonic equivalent of E♭ (E flat), meaning they sound the same but are notated differently. This note plays a crucial role in many chords and scales, contributing to the overall harmony and melody of a piece.