F# minor is a musical key that consists of the notes F#, G#, A, B, C#, D, and E. It is often associated with a somber or melancholic mood, making it popular in various genres, including classical, rock, and jazz. The key signature of F# minor has three sharps, which are F#, C#, and G#. In terms of scale, F# minor is the relative minor of A major, meaning they share the same key signature. The F# minor scale can be used to create melodies and harmonies, and it serves as a foundation for many compositions. Notable works in this key include pieces by composers like Johannes Brahms and Frédéric Chopin.