When the concertmaster has the oboe (I think) pull a A for the orchedstra to tune, is it just the strings that have to do this?
The only instrument I can play is the Jew’s harp, so not in a position to say, but assume brass and woodwinds don’t have to tune up, correct?
At concerts, never have been able to see other than the string sections, so can’t tell what the others are doing.
Every instrument tunes except the ones that cannot do it on the spot, like a piano. It’s common practice for the strings to begin, after the oboe, then the other sections chime in.
The kazoos are last. 
Yep, they all tune, and in some cases you’ll hear sections tune separately, and not necessarily beginning with the strings - in fact, strings-last is a common way to arrange it, so the leader can co-ordinate which sections are tuning before sitting down.
Brass instruments have a particular sliding mechanism for these fine adjustments, with woodwind it’s about repositioning the head joint, and timpani are tuned by pedals. It’s less useful to some instruments than others - for example tuning a trombone to an A is pretty ineffectual, because it’s just one slide position rather than the fundamental tuning of the instrument. But they cope, and to tune different sections to different notes would in any case introduce other problems.
Oh, and the harpist starts tuning half-an-hour before the concert. Seriously.
And is seriously f&*#ed if the ensemble A ends up different than the one they tuned to. This happened in a concert I did last year. The harpist was like a quarter tone low. It was awful.
In the U.S., at least, winds and brass always tune first. It’s very bad form for string players to start tuning when it’s not their turn.
It’s also bad form for the trumpets to do some last-minute practice on their solos while the strings are tuning…but does that ever stop them? 
When harps or pianos are involved, why doesn’t the orchestra tune to them?
Tuning harps and pianos takes a very long time. You have to adjust approximately six billion little nuts to get each and every string at the correct tension.
One would hope a decent concert-hall piano has already been tuned accurately to A440, so an oboe playing that pitch will be fine. If the piano is not tuned that well, than the oboe may tune to the piano beforehand. However, if the piano’s not been well-tuned, it’s not even correct within itself, so aligning the whole ensemble with just one note of many is of no benefit.
It’d be hard to tune a whole orchestra accurately to a harp, because of the simple lack of sound from the single string. Plus, they’re temperamental, so even if you’re in tune with the harp at 7.30pm, there’ll be things awry by 8 o’clock. It’s not all that unusual to see a harpist tweaking individual strings mid-concert.
Final point - the harp and the piano are two of only a few instruments that will be only using equal temperament (tuned percussion being the others). All other instruments deviate from equal chromatic divisions in various ways, particularly the strings.
A harp would also be hard to tune to as it is relatively quiet.
I’ve played the bassoon and violin in orchestras over the years, and the reason I’ve heard is that we tune to the oboe because the oboe can’t tune to us.
Thanks, guys, for all that fascinatin’ information.
Always heard that oboe musicians are all a bit strange due to the difficulty of playing a double-reeded instrument, but now I can see that harpists might be a little odd too, and for good reason! 
It’s because the oboe has a loud and quite “clean” timbre and is very easily heard. There’s no mistaking exactly what you’re hearing when the oboist plays that nice long A.
A very nice way of saying that the Oboe has a flat, non-reverberating, relatively plain sound.
Bah. Who wants to listen to strings anyway? All those people would listen to a marching band if they had the chance.
They could go and stand in the rain and do that if they want, but if they want the comfort of a concert hall, they’d better shut up and listen to the slow movement
Nah, because a marching band still has woodwinds. Gotta listen to a drum corps.
Very close to what I’ve been told. I’ve been told the oboe produces the fewest overtones, hence, is the best instrument to tune to because the primary pitch is the strongest.
As a side note, although I’m sure most strings tune to concert A, most woodwinds should tune to a different note. Since most adjustments are done at the neck of the instrument, you want to tune to a note that uses as few keyholes as possible. I played the clarinet in band; for lack of oboes our band tuned to the lead clarinetist. We frequently tuned to concert G because the clarinet could play it with very few fingers.
Alright, Doper trumpets! Are we gonna take snide comments from the drum line? NO!
<woodwind geek>
Nope, nope, nope. The first poster had it right-- the oboe is the hardest instrument to tune outside of the piano and harp. There is no neck on an oboe (unlike other woodwinds), just the butt end of the reed, and that is too short to make any difference. There is some leeway with your airflow and tongue position, but not a whole helluva lot. However, it’s enough that if they don’t want to DIE, the oboist will check to make sure that they are pitched to A440 before tuning the whole orchestra.
In symphonic wind bands (the ones that kick the strings to the curb) the tuning is usually done by the concermaster, a clarinetist. I can’t tell you how many times our oboe player has literally screamed about the band being pitched at something other than 440. He’s threatened to walk out, and understandably-- if we’re all tuned to, say, A436, he doesn’t stand a snowball’s chance of sounding good.
BTW, the wind instrument with the most aggravating tuning is the saxophone, which I think has a lot to do with why they still haven’t been all that welcome in symphonic music. Tuning them manually is a form of hell, and every little bump & blemish in your mouth (and therefore your airflow) will affect the pitch. Eventually you learn to fine tune a sax with nothing but your lip tension.
</woodwind geek>
I’m surprised it has not been mentioned with all the talk about the oboe, but probably all you musicians know it so well you have not bothered. On the other hand, it would be a pity if somebody did not know the saying about the oboe:
It is an ill wind that nobody blows good.