Which minor key includes one sharp?

The minor key that includes one sharp is E minor. In music theory, the key signature of E minor contains one sharp, specifically F#. This sharp is a crucial note in the key, as it contributes to the overall harmonic and melodic structure of compositions in this key.

E minor is the relative minor of G major, which also has one sharp in its key signature. This relationship is foundational in understanding how minor keys are derived from their relative major keys.

Understanding key signatures is important for musicians, as it informs which notes are to be played sharp or natural within a piece of music, thereby affecting the overall sound and character of the music performed in that key.