tuba

The tuba is the largest and lowest-pitched brass instrument, providing the bass foundation of the brass section in the same way the double bass supports the strings. Its wide, conical bore produces a rich, warm tone that blends well with the other brass instruments and with the full orchestra. Tubas come in several sizes: the contrabass tuba (in BB♭ or CC) is the largest and is standard in orchestras, while the smaller bass tuba (in F or E♭) is common in British brass bands. Wagner introduced the Wagner tuba, a hybrid instrument used in the Ring cycle. The tuba can be surprisingly agile and expressive — Vaughan Williams wrote a tuba concerto that showcases the instrument's lyrical capabilities.