Ben wrote:My guess is that Brian is trying to say the independence of the individual tones has collapsed into one composite sound (possibly similar to organ stops). I have rarely heard this effect achieved, one remarkable time during a performance of Mahler 3: the combination of an oboe & flute to create a novel sound that was so remarkable, I almost stopped paying attention to my rest counting in sheer awe of the beauty.
Yeah, it's difficult, but not impossible, of course.
The cool thing about pipe organs, though, isn't that they're in tune (they're not, but more on that in a sec), but that they're balanced and well-supported. Every line is meshing with the others and coming out as a mass of sound, and the wind support just doesn't waver, either.
They're "out of tune", though, even if they've been equal-temperamentally-tuned. Remember that when chords sound the smoothest, the pitches aren't smack in-tune on an electronic tuner. As jsmn4vu alluded to, unless you're going to just stay in one key all the time, equal temperament is best. That way, it sounds reasonably in tune in all keys, instead of fantastically in tune in one key (and maybe its relative minor) and horribly out of tune in other keys.
Music ensembles (especially wind ensembles, IMO) have an advantage in that the players can adjust the pitches to make everything sound more in-tune than an organ or a guitar can manage. Compared to equal temperament, a G will need to be a little sharp if it's the 5th of the chord, and a little flat if it's the 3rd.
Here's a trick -- get two players (preferably the same instrument),
three tuners, and an observer (preferably you). Have the players tune up, then have them play an open fifth, assigning one to play the root and the other to play a fifth above. Put two of the tuners on the root player, back-to-back, so both the player and the observer can see how in-tune he's playing. Let the fifth player look at his tuner and try to play his note perfectly in tune according to the tuner -- despite how bad it sounds. Then, turn his tuner around so you can see it, and have him play again, adjusting his pitch so that the open fifth interval sounds really, really good. Watch what happens with his tuner once the interval sounds perfect.