Contrabass Trombone

The contrabass trombone is usually pitched in F.
The range of the contrabass trombone
(excluding fundamentals or pedal notes)
demanded by Wagner is from E1 to E4,
though composers since then have required
notes as low as B-flat 0.
Wagner's Der Ring des Nibelungen used the
contrabass trombone for the first time in the
opera house. He had a horn with double slides
built by C.A. Moritz.