I wonder if GPO Advanced will feature a Euphonium? I don't think GPO Advanced would be complete without this awesome brass timbre.
I truly love the sound of the Euphonium, it's often called a tenor Tuba but you can hardly call a Euphonium a tenor Tuba because the timbre really is completely different to a Tuba, comparing a Tuba to a Euphonium is a bit like comparing a contrabass to a cello. It's used in a lot of marching bands, but it's also used in less common orchestrations.
It's got a lovely intonation and timbral quality that I could never find in any other brass instrument. The harmonic resonance is like a Tuba but the timbre is much, much richer with a sonic depth and brightness - providing that perfect british brass band/orchestral timbre that many british composers have been looking for.