Flat keys are a type of musical key that has a flat note as its tonic, or home note. For example, the key of B♭ major includes the notes B♭, C, D, E♭, F, G, and A. Flat keys are often used in various music genres, including jazz, classical, and blues, providing a rich and warm sound. In music notation, flat keys are indicated by flat symbols (♭) placed on the staff. Each flat key has a specific number of flats, which can be found in the circle of fifths. Understanding flat keys is essential for musicians as it helps them read and perform music accurately.