German and American Tubas and Trombones

[glangfur]

This just occurred to me this morning, from a discussion on the trombone forum: http://tromboneforum.org/index.php/topi ... 0.html#new" target="_blank

If American-style tubas, with their smaller bore through the valves and larger bell flares, are more conical than German-style tubas, with their larger bore through the valves and smaller bell flares...then American-style trombones, with their (mostly) single bore slides and smaller bells, are more cylindrical than German-style trombones, with their predominantly dual bore slides (generally starting smaller than the comparable American instruments) and larger bell flares.

Anybody got any particular idea how we ended up this way?