Over on The Rittenhouse Review, James Capozzola has written about a concert he attended at the Philadelphia Orchestra's new hall. In an "update", he asks why the orchestras always tune to the oboe, and he gets an answer, but he seems a bit foggy about some of the particulars -- specifically, what "A 440" means.
Well, they tune to the note "A". I'm not sure exactly why it's that note as opposed to, say, "E", but that's what they're doing. So, when a conductor ascends the podium at first rehearsal and asks the oboe to "Give us the A", he's asking the principle oboist to sound an "A" so that the orchestra can tune. Easy enough.
So what's this "440" business? That's the frequency of the particular "A" -- 440 hertz. (I think it's hertz, anyway. It's been a while since I did this stuff on a regular basis, and even then I didn't pay much attention to the scientific stuff underneath it all.) If we define "A" as 440 hz, then it follows that a "B" one full-step up will have a higher frequency -- 455 hz, perhaps. (Again, a guess. Don't get indignant with me if I'm colossally wrong!) And a B-flat, in between, will be roughly halfway between the two. OK?
But "A = 440" isn't carved in stone. If an orchestra wants to tune slightly flat, the principle oboe will sound the tuning "A" at, say, 438 hz; likewise, they can tune slightly sharp, at "A = 442", perhaps. Sharpness is generally preferred, especially by the string players in an orchestra, because sharpness yields a brighter, livelier tone. Playing flat is generally viewed as "icky". ("Icky" being, of course, a precise musical term. You can look it up.)
Now, if "B" is 455 hz assuming "A = 440", then the musicians in the orchestra will naturally play a "B" slightly sharper than that if they tune to "A = 442". The professional musicians who fill the ranks of America's orchestras (and the world's, for that matter) have good enough ears to adjust their tuning of all the notes (or "pitches") at their command, based on whatever they have established the "A" to be. This is what is meant by the term "relative pitch", and it is an absolutely essential ability for orchestral musicians to possess. If a musician, a trumpet player perhaps, was to walk into an orchestral audition and display technical proficiency on par with Wynton Marsalis's, but also displayed the relative pitch of an average high school or college-level player, the trumpeter would not get the job, if (s)he were to even be called back for the second round of auditions. Tuning is the bedrock of ensemble playing, and that little ritual orchestras go through at the outset of each concert serves a very real purpose.
And it's not, to castigate a horrible pun foisted on the world by a onetime band director of mine, the world premiere of the newest composition by Chinese composer Tu Ning.