Euphonium. Nominal pitch: C.
Technical description: Silver-plated brass. The 4th valve is a 'trilateral' valve, the shorter (C) and the longer (G) windways both leave valve at upper ports, pass through tuning-slides and re-enter the valve at lower ports. There are thus two independent main tuning-slides. The bore diameter increases through both the 4th valve loops and tuning-slides, so the lower coquilles in the 4th valve piston are of larger calibre than the upper. The moving part of the main tuning-slide for C has one outer leg (the narrower) and one inner (the wider). Valve type: valves 1-3 the normal Périnet valves; the 4th valve Périnet-type. Repair History: In the past, the C main tuning-slide was extended to put instrument in B♭. The G main tuning-slide was only slightly extended, so the 4th valve then gave a lowering a minor third. A new C main tuning-slide was made for the instrument in 1992-3 but the G main tuning-slide was not restored to its original length.