CC Tuba = BB Tuba?

[TubaofGilman]

I have a question for everyone. Sorry if this something that I should know.

Here’s the question. I am playing a Mack Brass 410 CC.

If I hold down the fifth valve, will the tuba play as a BB using

BB tuba fingering?

[Mark Horne]

Not really. Playing a Bb on a CC tuba will be in tune with 1st valve only. Using the 5th instead, you will be a quarter step flat. You will be less flat as you depress more of the 1st-4th valves. For instance the low F fingered 4-5 will be in tune (just as low F is played as 4th valve on a Bb tuba). There have been CC tubas made (such as a B&S Neptune) that have a shorter 5th valve slide designed to allow playing in BBb while the 5th valve is in the loop. There are some tuning compromises but it does work.