Euphonium
Low B♭ Bügelhorn, tenor tuba.
What it means
The euphonium is a brass instrument of the Bügelhorn (saxhorn) family in B♭ with a wide, conical bore, usually four valves, and a large, upward-pointing bell. Its range corresponds to that of the trombone, but its sound is fuller, softer, and darker. Two ways of notation are in use: at sounding pitch in the bass clef, as is usual in German wind music and in the orchestra, or transposing in the treble clef, as in the brass band tradition, where a written c′ sounds as B♭. Closely related, and partly used with the same meaning, are the names tenor tuba and baritone, the latter usually meaning a more narrowly bored instrument.
Musical use
In the concert band and the brass band the euphonium is the singing instrument of the middle register; the great melodic lines fall to it, and it has an extensive, technically demanding solo repertoire. In the symphony orchestra it appears less often but is occasionally called for expressly when a composer seeks a tenor sound between horn and tuba. Its agility is remarkable: despite the low register, fast runs and wide leaps are readily executable, because the valve technique corresponds to that of a trumpet.
Performance practice
Use the fourth valve to correct the low valve combinations, which otherwise lie too high, and learn the usual alternative fingerings. The airstream should flow broad and calm; the large cup of the mouthpiece rewards fullness instead of pressure. Practise slurs across wide intervals, because the partials lie close together here and accuracy demands a conception of the sound. Watch for a posture in which the weight rests on the thigh or a stand and the right hand stays free. Empty the condensation often and keep the valves moving smoothly; with the many bends, water collects quickly.
Remember that the euphonium demands considerable amounts of air in the low register and the tone easily blurs there: articulate more distinctly than would be necessary in the middle register. With transposing notation in the treble clef, it is worthwhile to master both ways of reading, because parts are printed differently depending on their origin. In an ensemble with trombones, the articulation has to be matched, since the soft attack of the euphonium otherwise falls behind. Practise slurs across large intervals, because the repertoire often demands them.