TUBA. A generic and somewhat vague title given to the Bass instruments of the Saxhorn family, also termed Bombardons. All of them are furnished with valves, and are liable to the usual defects inherent in this mode of construction. But as they have a large mouthpiece, and require a very loose embouchure, more can be done towards correcting harmonic imperfections of the scale by the player than in acuter instruments of the same character. Tubas are made in many keys, in F in Germany, in E♭ and B♭ in this country: as however they usually read from the real notes, their parts require no special transposition. Their introduction into the stringed orchestra is entirely due to later composers, and pre-eminently to Wagner, who often obtains fine effects through their instrumentality.