Music bridges the generation gap

Some of ''the sweetest sounds you ever heard,'' are emitted by the sweetest chorus you ever heard. An intergenerational chorus. On the surface, ''Close Harmony'' (PBS, Monday, 9:30-10 p.m., check local listings for premiere and repeats) concerns a Brooklyn Friends School music teacher who also trains the senior chorus of the National Council of Jewish Women Center for Senior Citizens. She decides to combine the two groups.

When teacher Arlene Symons made the decision to combine fourth and fifth graders with senior citizens, in order to smooth the generational gap, she first organized a pen-pal exchange between individuals in both groups. Where there was misunderstanding and little empathy, soon there was the beginnings of mutual appreciation and understanding.

Then they met and sang -- and rejoiced in each other. What until that point had seemed to be intergenerational irritations and antagonisms evolved into warm appreciation of individuality and idiosyncrasy, on both sides. And good music, too.

Simple true story, isn't it? Filled with choral counterpoint and intergenerational music.

But ''Close Harmony'' is much more than a documentary about singing. It is about the natural affinity between the young and the old, the unnatural gulf that seems to separate them in contemporary society, the simple ways in which that gulf can be bridged.

''Age is as old as you want it,'' says one of the senior citizens. ''Close Harmony,'' presented on PBS through WNET/New York, produced and directed by Nigel Nobile, is as young as its youngest choralist. It hits a perfect E for excellence above high C.