Swiss glacier; HIKING THE GROSSER ALETSCHGLETSCHER

At night, all you hear are the cowbells, and when a lot of them are tinkling at once they sound strangely like the distant beat of Tahitian dance drums. Such was the music that lulled me to sleep the night before I took on the Grosser Aletschgletscher, the longest glacier in Europe.

Before turning in, though, I was treated to a curious show that has become a summer trademark of Riederalp, a farming and tourist hamlet perched on a mountainside in the Swiss canton of Valais. Riederalp, eight miles from Brig via a trolleylike train and then an aerial tramway, is alive with the sound of building these days, and the man at the center of the boomlet is Art Furrer.

Mr. Furrer is a local boy made good, a champion skier who went off to the United States in the late 1950s and parlayed his acrobatic ski skills into a tidy little business. He somersaulted through the '60s and early '70s, promoting resorts and ski wear from New Hampshire to Sun Valley, sometimes in person, sometimes on film, and in 1973 he came home to the cowbells and the split-log farmhouses to build a hotel or two.

Ironic, isn't it, that the inspiration for his hotel and restaurant format would be Vail and Aspen, which of course at one time themselves -- Vail especially -- borrowed on the Swiss ski chalet theme. As I sat down to dinner in the multi-tiered dining room, a ski film lighted up a large screen, the narration spilling forth in English. Costars of the film were a younger Mr. Furrer and his fellow Swiss ski instructor, the late Roger Staub, who once worked at Vail. For 20 minutes or so they led a merry, scary trail from the Rockies to the Rhone Glacier, with detours to Lake Geneva and the Arc de Triomphe.

Mr. Furrer meanwhile moved about the dining room greeting and farewelling guests. ''You see,'' he said, stopping by my table as I finished an appetizer of cheeses and dried meats known as Walliserteller, ''I learned something in the States - public relations. I am here every night to the very end. I tell them about hiking, skiing, anything they want to know.''

By morning, the music of cowbells had given way to the bang and clang of construction (more rooms being readied for the ski season), but in no time the glacier-crossing group I joined had left the din behind and was climbing upward through sunlit meadows. Normally there are 10 or 12 to an expedition, but we were closer to 30, several days of rain having caused a backup.

Our leader was Erich Venetz, a bearded ski instructor in winter who wore blue-gray knickers and a bright red woolen shirt on this shining late July day. All you need on the glacier are hiking boots, perhaps a sweater or light jacket to ward off the cooling draughts, and suntan lotion. Mr. Venetz carried some more serious gear, however.

High above the village we were joined by a German woman, Brigitte Michaelis, whose role was to describe the flora and fauna along the trail. Miss Michaelis was spending the summer on a study tour attached to the Villa Cassel, an imposing Tudoresque chalet that looms above Riederalp like the Edwardian remnant it is. Once it was the summer digs of Sir Ernest Cassel, friend of the young Winston Churchill and others (there are mementos from that period on display), and today it is headquarters for a nature conservancy, as well as a modest natural history museum.

As Miss Michaelis delivered her trailside lectures on the larches and pines and deer, providing her only-English-speaking pupil with a compressed translation, we hiked upward through the forest, finally arriving at a clearing beside our objective, the vast, inexorable glacier. If your notion of the longest glacier in Switzerland (22 kilometers) is of one towering pristine ice cube, you haven't seen the Grosser Aletschgletscher or any of its brethren. Perhaps a quarter-mile in width, it bore the color of a three-day-old Manhattan snowfall, caused by stone, rock and rubble imbedded in the icy surface.

We took a break on a rocky field - a moraine - on the glacier's edge, some of us cracking hardboiled eggs, others swigging fruit juice, nearly all applying suntan lotion. Then Erich broke us into three groups of 9 or 10 apiece and knotted each group together by rope, spacing us about 10 feet apart. Like three centipedes we started across the glacier, stepping gingerly past deep blue-green pools, or crevasses, up and down narrow ledges that Erich made negotiable by hacking out foothold with his ice pick, or Eispickel. We stopped here and there to inspect the yawning crevasses, Erich holding each curious rubbernecker by the waist as he or she leaned far over the swirling, booming font.

At last, an hour or 90 minutes later, we were on the other side of the glacier, relieved of our ropes and climbing like mountain goats to a rocky, sunwashed ledge for rest and sustenance. Far away, through a gap in the ring of white-capped mountains, I could see the unmistakable form of the Matterhorn.

On the recrossing I began to relax, to notice the hushed respect paid to the sooty mass of ice. ''He demands it,'' I said to myself, choosing the masculine pronoun Brigitte favored.

That night, back in Art Furrer's restaurant, the old hotdogger evinced surprise when I told him we had used ropes on the traverse. ''I lead groups myself,'' he said, ''and in fact I'm taking 25 people out tomorrow, and I'll bring the ropes along, but I'll try to cross without them. I think they can be dangerous unless you know how to use them.'' That left a question or two on my lips, but all of a sudden the Toots Shor of Riederalp was off on an expedition of his own, greeting newly arrived guests and spreading the good word on the Vail of the Swiss Alps.