Blues harmonica is a small, handheld musical instrument that produces sound by drawing air through reeds. It is commonly used in blues music, a genre that originated in the African American communities of the Deep South in the United States. The harmonica's expressive sound and portability make it a popular choice for musicians, allowing them to easily accompany themselves or others. The instrument is typically played in various keys, and players often use techniques like bending notes to create a soulful sound. Many famous musicians, such as Little Walter and Sonny Boy Williamson, have showcased the harmonica's versatility, contributing to its prominence in rock and folk music as well.