There was an excellent article in the New York Times over the weekend about the difficulties of playing Jazz at Carnegie Hall -- actually, the difficulty in surmounting the acoustic problems that make said Jazz difficult to hear.
"Opened in 1891, the hall has a large proscenium designed for unamplified
music; the room's natural acoustics enable sound to travel both back and
forth across the stage and outward into the audience. Today roughly a
fifth of the performances at the hall each year have amplified instruments —
often jazz shows put on either by JVC or other outside producers — and in
those cases the hall's natural strengths become weaknesses. "
The basic problem is that many concert halls that were built to accomodate large 19th century orchestras playing big, lush music for large audiences, and so they have extremely reverberant acoustics -- which is great if you're playing Mahler, but not so good for other things. The Times article discusses how
"Bands unaccustomed to only light amplification for their stage monitors —
the small speakers at the lip of the stage facing the musicians — often turn
them up beyond the room's capacity to handle the volume, creating sonic
Similarly, bass and drums can be hard for the room to handle. Tones in that
pitch range take longer to decay, and in a room that already has a lot of
natural reverb, like Stern, low-end music can become a jumble. Likewise, the
high frequencies of cymbals, played above a certain volume, can create a caustic
sound through the hall."
Unfortunately, much non-Romantic period classical music suffers in these halls too -- if the music has a lot of rhythmic detail that's intended to be audible, it can get completely swallowed up by the reverberations. I recall that New England Conservatory's Jordan Hall is widely regarded as first-rate, and for many kinds of music it is. But the performance of my piece Pulse-Point was undermined by the acoustics -- I had 16th note pulsation happening through almost the whole piece, and it turned into mush.
One solution to the problem, when handled well, is actually to amplify the instruments. When amplified, a larger proportion of the sound heard by the audience is coming directly from the instruments, so while the reverb level is also louder it's less out-of-balance. Reverberation is caused by sound bouncing off of the walls and ceilings and reaching your ear later than the direct sound, and in a big, reverberant hall, there are many, many surfaces sending you many reflections, but the sound source is still the same volume. Amplification ramps up the source sound -- and amplification with many speakers spaced through the hall (Bang on a Can amplified their recent Marathon in the cavernous Winter Garden of the World Financial Center this way) is even better, because it gets you closer to the source -- the perceived volume is higher, but the amount of sound going out into the room to get bounced back is the same. Recordings in these halls, with the microphones up close to the musicians, are often great for precisely this reason -- the reverberation is lush, but it's at a low volume in comparison to sound source. The recording of that performance of Pulse-Point is terriffic. Of course, amplification also comes with the hazards mentioned in the Times article -- especially if the guy running the house sound is accustomed to amplification in clubs where it's a completely different game.
Is there anything that composers can or should do about this problem? When writing for orchestra, bear in mind that the hall is an unavoidable part of the way an orchestra sounds. When writing chamber music, things that work great in small rooms will sound bad in orchestra concert halls, and probably vice versa, so it might be worth considering the venue for which you are composing. And composers might consider asking for amplification in large halls, and performers might consider playing with amplification even when the piece doesn't call for it.