Minor keys are a type of musical scale that create a darker, more somber sound compared to major keys. They are built using a specific pattern of whole and half steps, which gives them their unique emotional quality. The most common minor scale is the natural minor, but there are also harmonic and melodic minor scales that introduce slight variations. In Western music, minor keys are often used to convey feelings of sadness, introspection, or tension. Many famous pieces, including those by composers like Ludwig van Beethoven and Frédéric Chopin, utilize minor keys to evoke deep emotional responses from listeners.