THIS COLUMN might be titled: A Fable for Fidelitarians, or The Curious Death of the Symphony (with apologies to Louis D. Rubin Jr., author of The Curious Death of the Novel ):

Once upon a time there was a group of very talented composers known as Modern Composers, who wrote large-scale orchestral works known as Modern Symphonies and Modern Tone Poems. Some of these composers were named Stravinsky, Bartok, Strauss, Sibelius, Prokofiev, Shostakovich, Vaughan-Williams, and while each of these composers wrote music unlike that written by any of the others, they all were considered Modern Symphonists.

At the same time there was another group of people, some talented and some not so talented, known as Music Critics. They listened to the works of the Modern Symphonists and although often (if not most of the time) they listened to recordings of these works on low-grade phonographs that failed to reproduce the full tonal and dynamic ranges clearly, they were able to hear enough to reognize the music as Symphonic. Also, some of the Critics read musical scores which they felt counted for as much as actually hearing the musical sound.

They thereupon proclaimed to each other and to the world: "Aha! Now we know what a Modern Symphony is." This was a very astue observation, and they were quite satisfied with it and with themselves.

Time passed and eventually all the composers in the group known as Modern Symphonists were dead, or had stopped composing. However, there were some new people around who also wrote large-scale orchestral works and who insisted that these works too were Modern and Symphonic.

"Heavens, no!" replied the Critics. "How can you be Modern Symphonists? Modern Symphonists are composers who write Modern Symphonies, and we all know what a Modern Symphony is. It is a large-scale orchestral work written by someone named Stravinsky, Bartok, Sibelius, et al."

"But we are not those Modern Symphonists," said the new people. "We are Bernstein and Copland and Tippett and Thomson and Harris and Somers et al."

"Don't be silly," the people known as Music Critics declared. "Unless you write the same kind of music as that written by Modern Symphonists, it can't be Modern Symphonic and you can't be Modern Symphonists."

"But those composers are inactive or dead," the new composers said.

"True," replied the Critics, "and so is the Modern Symphony."

The new composers, who had not learned proper respect for the Critics, were not to be put down. They went on: "We are composing for people who know the score even though they may not be able to read one. We are composing with an ear to the sound of music, in contemporary idiom, which the modern techniques of recording and of playback are able to capture and release for vast audiences."

At this the Critics were so shocked that for the first time in history they had nothing to say. The new composers pressed on: "What do you call the music we compose?"

"We cannot say," muttered the Critics, "because now that the Symphony is dead, we do not keep up with current music any more. And we see even less point now then ever in going in for all that hi-fi and stereo machinery since the Symphony is dead."

Moral: Nothing is quite so dead as a dead definition, unless it is a dead Critic.