B minor

B minor is a minor scale based on B. The harmonic minor raises the A to A. Its key signature has two sharps.
Its relative major is D major, and its parallel major is B major.
In Baroque times, people thought that B minor was the key of passive suffering. Christian Friedrich Daniel Schubart (1739-1791) said that it was a key that was complaining gently and quietly, something that matches Bach's use of the key in the St. John's Passion. By Beethoven's time, B minor had changed in people's minds: Francesco Galeazzi wrote that B minor was not suitable for music in good taste, and Beethoven labelled a B minor melodic idea in one of his sketchbooks as a "black key".
The chord was famously used as the first chord in Pink Floyd's 1979 hit "Comfortably Numb". The second movement of Rodrigo's Concierto de Aranjuez, one of the most famous compositions for the classical guitar, is in B minor.
It is a common key used in rock, folk, country and other guitarist-based styles because a guitar is naturally tuned so that all the open strings are notes in B minor.