I've attempted to make this as non-technical as possible partly for the non-musician, but mostly because while I'm writing about a technical issue, I believe that when you discuss the relevance of a technique or medium in art, you're making a philosophical argument which can only be clouded when you cloak that argument by sending it into battle wearing a plate-mail of technical jargon.
Recently, composer Ken Ueno wrote an interesting article in the NY Times which included some concerns towards western classical musical notation. Now in his case, both his concerns and technical requirements demand he tackle this, since for his pieces it's a major issue. To horribly abbreviate and then leap off at a wild tangent shortly afterward, I'll just say that he creates a sort of extension of notation in order to accommodate the different extended techniques he employs such as multiphonics and if he didn't do this difficult task, it would obviously be impossible to transmit these devices to the performers. So now the wild leaping tangent part: A lot of modern composers feel this discomfort with the traditional notation as well, and currently it's largely agreed that a composer should be as specific as possible in their scores. Of course, there's some forms you can write in where nothing could be further from the truth, such as all works employing some kind of aleatoric principles.
So here's my idea: western notation wasn't really meant to be specific. Really, not at all. It's even less helpful than a fake book or lead sheet is to a jazz musician, where the element of improvisation is expected. Take the score of the first movement of Bach's BWV 1001, the solo sonata for violin, which helpfully you can see here (fear not, you can see what I mean even if you can't read music). Notice that for the most part, it's a series of chords linked together by runs. Some musicologists believe that this piece is one of the first times a composer sat down and wrote out those linking runs, and that previously a performer would just be expected to noodle from chord to chord, the exact runs being governed by schooling, fashion of the day, and good taste. Bach, ever the shrewd composer, knew that in any age good taste is always in short supply, and simply got more specific for the performer, and we're much the richer for it. That's a good example of not leaving it to chance.
Now let's look at two famous recordings of the first section of his Goldberg variations, by Daniel Barenboim, the other Glenn Gould. When you compare what notes in the treble line up with which notes in the bass, we've got a surprising difference. In fact, often times what makes a terrific Bach player for me is the amazingly subtle push and pull between the lines that a pianist such as Jeremy Denk can do, a type of micro-coordination that I'm not sure many of the general public can always pick up, but I have the misfortune of being able to hear 100% clearly yet cannot @#$%#& play unless I wrote it. Is this an artistic liberty of interpretation, or is this freedom intended and expected by the composer? Ok, that's probably subjective at least, and too close to call in the best of cases. I can imagine flotillas of bespectacled professors sharpening the patches on the elbows of their corduroy blazers in preparation for battle on that subject. Let's try one final example...
When you examine the scores to many of Chopin's works, you simply cannot make those gorgeous colors happen if you play it 'straight'. Try imputing a Ballade or Nocturne into a computer, and hear what it sounds like...you can recognize it, but you almost wish you didn't. Just as in the age before Bach, there's an expectation that you'll fudge some things this way or that to make it just right. Did Chopin think much about people other than himself performing his works? The answer seems to be an unhelpful 'yes and no'. There are a few quotes that have survived about his thoughts on rubato, but let's give a thought to the compositional process he must have gone through to create them...that the rubato came first, and the notation came second. Meaning he wrote the piece, with beautiful pauses and rhythmic tugging, then later went through the terrible and laborious ordeal all composers undergo, that of making the notes on the page resemble the sounds in the creator's head and fingers. Could he have written out EXACTLY the performance he wanted? Try playing Chopin "correctly" into a computer notation program via keyboard and MIDI...even if you play with an astounding and robotic precision, you'll see some pretty complex measures popping up on your screen (cheating with FlexiTime doesn't count, naughty children!).
So really I would respectfully suggest western notation was never (until recently) expected to be the beginning and the end of the story. Performers weren't intended to be radical fundamentalists of a composers perceived intentions, and a quick survey of recordings with composers conducting or performing their own works will teach you that we frequently have amazingly poor taste even when it comes to our own works. I plead the case against ourselves as stemming from spending too much time immersed in the work...a composer like John Adams who is also a splendid and tasteful conductor is simply a scary freak of nature. John Mackey wrote he stopped conducting his own works when he realized the musicians were actually and terrifyingly following him...closely.
Composers need to put the important bits in, the things that really can't be left to chance. Then step back and believe that the right performers will breathe a life and magic into your notes that perhaps you didn't even expect to bloom on that gnarly vine of a part you wrote for them. Perhaps "Trust, but verify" isn't a good policy for modern notation...Put all the notes in, and be as specific as the piece demands, but after that, allow room for each chef to season their food. Even Mahler said that many of the markings in his scores were to be adjusted by the conductor based upon the responsiveness of the concert hall, and the tiny 4-minutes of piano rolls he made in 1905 shows a great deal of rubato in his own piano versions of some of his symphonies. I put down the details, but leave a note (usually) saying what details I expect a performer to feel free with. If I say to move from piano to forte...well, I mean it's softer and it should get louder. How soft it was and how loud it got would be utterly pointless for me to believe I had a reasonable say in. What size is the room? How many sound deadening bodies are in it. Is it humid? Cold? Recording or performance? These all play a huge role in the effect, and the composer MUST trust that a conductor or performer DOES have the ability to employ good taste...afterall, they DID pick your work to play, right? Shows some pretty awesome taste already! So make sure your intentions are clear, and trust them to adjust to produce the best effect for the situation. The last thing you'd want is some awful sound made that's defended by the words, 'I know! But he wrote it in the score that way!'
