Seems like a basic question, but I am a bit confounded by it. For trombone, I push the tuning slide all the way in and tune everything with the 3 foot long tuning slide in my right hand. For trumpet playing I tune the concert Bb using the main tuning slide and don't worry about anything else (like most trumpet players I know). But having recently picked up a Wessex Dolce Euphonium and not exactly sure what to do with all of the valve slides. It seems obvious to tune the main slide to the 3rd partial Bb. And my thought is then to tune the 2nd valve slide to the A below it and the 1st slide to Ab. But what to do with that pesky 3rd valve. I don't see using it by itself to play the G, so I wouldn't tune it to that. Makes more sense to me to tune it to the Gb or the Db in the staff (bass clef) with 2nd and 3rd valves depressed. Doesn't make sense to me to tune the 3rd valve slide to the C (1 and 3) in the staff as I would tune the 4th valve to that note.
And I off base here. Overthinking it. Going the wrong direction?
After a first orchestra rehearsal using the Euph, I quickly found out that I should probably use the 4th valve for the C above the staff, 2and 3 for the Db, 1and 2 for the D above the staff in order to stay in tune with the orchestra, but I am not sure how that plays into the whole tuning of individual valves.
Ideas?