Trombonium

{{Short description|Marching valve trombone}}{{Infobox instrument

| name = Trombonium

| background = brass

| image = 00 Tromboniums.jpg

| classification = * Wind

• Brass
• Aerophone

| timbre = * Trombone

}}

The trombonium is a brass instrument formerly manufactured by H.N. White Company and Conn-Selmer.{{cite web|title=H.N. White Trombonium|url=https://www.hnwhite.com/Trombonium%20Page.htm|website=The H.N. White Collection via internet archive|accessdate=10 July 2016|archive-date=10 November 2006|archive-url=https://web.archive.org/web/20061110012807/https://www.hnwhite.com/Trombonium%20Page.htm|url-status=bot: unknown}}{{cite web|title=Conn 90G|url=https://cderksen.home.xs4all.nl/Conn90G1970image.html|website=The Conn Loyalist|accessdate=10 July 2016}} It was unveiled by H.N. White in 1938 and was manufactured until the mid 1970s. The trombonium has the same timbre as a regular trombone except in a smaller, more compact form. It was originally designed to be used as a marching trombone, and has valves rather than a slide thus superficially resembles a tenor horn or euphonium. It was used by the University of Southern California Marching Band and on a handful of jazz recordings (e.g., Jay and Kai + 6).