The baritone saxophone
The baritone saxophone, more commonly known as the bari sax, produces a sound about one octave lower than the alto sax. The bari Sax, with its bigger mouthpiece and overall size, produces a steady tone easier, but requires a lot more air to create a tone. It was created in 1840 by Adolphe Sax. Adolphe Sax also invented the tenor sax and the alto sax, among many others.
The baritone saxophone, much like the rest of the saxophone family, is used in a variety of musical styles. The baritone saxophone part often doubles parts with bass clarinet, tuba, trombone, and bassoon.