Question for wasnex: When did the army quit the tuba requirement for bandsman? That was one of the reasons I didn't seriously consider the army band after auditioning. I could play some tuba but the thought of being stuck in post band somewhere playing tuba made my elitist self say "No, thanks".
I was not aware this had changed.
I believe the Navy also had a general expectation that players doubled on tuba and bass guitar. So the Army was not all that unusual.
The Air Force was the outlier, as they expected players to double on upright and bass guitar. Those who do not double on upright don't tend to go as far as those who do.
AF band field bands are generally broken down into two parts. One side includes one or two full-time cover bands. The players on this side of the house typically also play jazz trio and various solo engagements.
The other side of the house is built around the personnel required to field a concert band. The concert band breaks down into various smaller ensembles that typically includes big band, woodwind quintet, brass quintets, possibly a part time cover band or other specialty group, and jazz trio. Vocals, guitar, keyboard, and trumpet also tend to do solo background or ceremonial jobs. Bassist on this side of the house are expected to play upright bass at a high level in both classical and jazz styles, and to double on bass guitar as needed.
Most AF tuba players are pure legit and do not double on bass guitar or upright. They play primarily in concert band, brass quintet, and maybe Dixie band if the unit has one.
In my experience, the AF typically had higher quality musicians on average than the other services. There were very few members who did not possess at least a Bachelors. Many had completed graduate level work.
The Army and Navy had some super talented players, but they also had many players who were not really professional level IMHO. I believe there were multiple types of bands that had different quality standards. AFAIK these different levels had different quality standards.
The AF has two types of bands. There are two premier bands and they have different promotion authority and somewhat higher quality standards. People who are hired into one of the premiere bands usually stay there for the rest of their career.
The rest of the AF bands are called field bands. There are plenty of players in the field bands with enough skill to be in one of the premiere bands, but overall quality is a bit lower.
There are currently two small (named) bands that are no longer technically independent units. One of them is essentially a geographically separated detachment of a field band. The other is attached to a Major Command rather than belonging to parent band. Personal in these smaller bands are still considered part of the field band program. So they are expected to have the same skills and quality expectations.