Summer in Aspen: between musical events you can go hot-air ballooning

As if its high blue skies, myriad sporting choices, and multifarious restaurants weren't enough, Aspen rings all summer long with one of the best and oldest music festivals in the land.

Until Aug. 21 this year, the Aspen Music Festival will spread itself all over the appealing little one-time mining town, inveigling and enchanting even those who come for other reasons. In its 34th year, the festival was recently called ''the Salzburg Festival of the US,'' by a visiting Berlin critic. ''We're not that presumptuous,'' a festival official told me one bright Rocky Mountain afternoon, ''to compare ourselves with Salzburg, but we're getting there.''

Aspen is, of course, better known for winter and skiing, but anyone who visits in summer will find more than enough to do between music events. Indeed the common line among Aspenites goes something like: ''I love to ski, but summer is the best time to be here. It's a little too frenzied in the winter.''

Aspen's is the ideal setting for summer culture (there is a ballet festival until Aug. 13, a playwrights conference about then, a FilmFest in September), neatly sequestered as it is at a rarefied 8,000 feet well off the beaten freeway. It's a three-hour drive from Denver over Independence Pass (closed in the winter, making the trip much longer then), or a straight pass over the mountains by small plane.

Though the music festival plans its biggest year ever in 1984, for its 35th anniversary, there is nothing minor about the 1983 schedule. Most of the main events are held in the soaring white festival tent on the edge of town, but if the 1,800 seats are sold out, you can do just as well, sometimes better, lying back in the surrounding meadow in T-shirt and shorts, letting the music play over you. Unlike other festivals, Aspen has two or three events a day - in the tent, in the auditorium next door, in schools and churches. Young musicians may strike up a piece in the middle of the downtown mall or on a bridge over the Roaring Fork, and opera scenes are given outdoors to publicize later performances.

Classical music is the rule at Aspen, but there are plenty of modern compositions and a raft of jazz. Buddy Tate and George Shearing are among the 1983 performers, and Martha Schlamme will do her wonderful cabaret numbers at the turn-of-the-century Jerome Hotel. (Tickets can be reserved through Music Associates of Aspen, PO Box AA, Aspen, Colo. 81612; for lodging phone Aspen Central Reservations at (303) 925-9000.)

Music is only part of the Aspen summer melody, and if you're wanting for things to do, the people at the pretty gray Victorian chamber of commerce office at 303 Main Street have all sorts of suggestions. There are hiking trails of all difficulties, hot-air ballooning with the Unicorn Balloon Company, glider rides with Soar Aspen, bike rentals, camping information, hotel and restaurant lists.

Aspen has been described, not erroneously, as the best little food town between San Francisco and Chicago. The odds-on favorite for breakfast is the Jerome Hotel dining room, a big sunny enclosure with mirrors and stained glass and hanging plants and a hearty menu that includes Walnutta Waffles. The Jerome, about to become a serious hotel if its planned renovation is carried out, is a throwback to silver-mining days with its tiled lobby floor and old wood cage.

At lunchtime the top choices are Pour la France and the Ute City Bank. Pour la France, good for soups and sandwiches, is a recently rebuilt French-style cafe at 411 Main Street whose owner is determined it will not become a ''croissantier.'' ''We hope to be around long after that fad is gone,'' he says. For dinner, two of the better bets in a town frankly overflowing with eating places, some of them overpriced, are Maurice's and the Parlour Car, a period railroad car once used by Teddy Roosevelt.

Aspen's architecture is a happy melange of Tyrolean-style inns, sandstone 1890s office buildings, and gingerbread Victorian houses, some in outlandish color blends of purple, mauve, and pink. All building is under strict control, so much so that the town supermarket and shopping center - done in a uniform, green wood scheme - resembles a fetching old-fashioned cannery. In the heart of town there is a series of no-traffic malls with brick walks, wood benches, and maturing little aspens.

Aspenites are into sports and fitness with a vengeance. I joined them on their splendid jogging trail - a paved-over Rio Grande rail route along the Roaring Fork - and followed a popular bike path on the road to Independence Pass with a borrowed machine (there are rentals available), finding the 8,000-foot elevation taxing but not prohibitive. I stayed in a comfortable lodge called the Fasching Haus, happy with the lowered summer rates. When I drove out of town one blindingly bright day, the snow still clinging to Buttermilk Mountain, I thought about those frenzied skiers and how much they are missing by avoiding the Aspen summer.