The acoustical identity of the bass trumpet

The bass trumpet has the same compass as the tenor trombone. It emerged as a recognised species of brasswind in the second half of the 19th century, a time when valve trombones were far more prevalent than now. The organological literature fails to provide any acoustically significant basis for differentiation between trombone and bass trumpet. Measurements of acoustical parameters such as input impedances of some bass trumpets, slide and valve trombones from the Edinburgh University Collection of Historic Musical Instruments and other sources are presented alongside results from sounding these instruments using artifical lips. The possibilities for correlation of physical, acoustical and performance characteristics are explored. It is believed that the systematic detailed measurements underpinning this paper have not been made previously, and that the synthesis of acoustical with physical measurements can be a valuable approach in the study of historic brass instruments of all kinds.