The "Blues Harp," also known as a harmonica, is a small, handheld musical instrument that produces sound by drawing air through reeds. It is commonly used in various music genres, especially in blues, rock, and country music. The instrument is played by either inhaling or exhaling, creating different notes and tones. Blues harps come in various keys, allowing musicians to play along with different instruments. They are often made of metal and plastic, with a series of holes that correspond to specific notes. Many famous musicians, such as Little Walter and Sonny Boy Williamson, have popularized the blues harp, showcasing its expressive sound and versatility.