When Sviato-slav Richter turns up unexpectedly at your music festival to play a recital, you know you've got something.

As it happens, the famed Bavarian resort town of Bad Kissingen (the "Bad" stands for "bath") has had something for a good many years. First there is the town itself, nestled an hour and a half east of Frankfurt amid the hills of the Bayerische Rhoen. As its beautiful parks (roses everywhere) and fountains soothe the spirit, so its natural mineral waters are said to do the same for the body. So much so that Bismarck, a frequent visitor in the 19th century, is on record as having said he owed the second half of his life to Bad Kissingen, and not coincidentally the stone tower that overlooks the town today bears his name.The last three years, moreover, it has had a summer festival. Dubbed "Kissinger Sommer," it is principally the work of Bonn arts entrepreneur Kari Steff-Wolfsjaeger (her doctoral work was in the dramatic works of Henry James) and is no less wide-ranging in its outlook.

Designed to take advantage of the spa's impressive complex of concert and recital halls (including an indoor/outdoor band shell and even an opera house), for 3 1/2 weeks each June and July it offers a decidedly international mix, laying particular emphasis on artists from the Eastern Bloc - e.g., East Germany, Czechoslovakia, even the Soviet Union.

For example, in addition to Richter, performers this year included the Moscow Chamber Academy, the Slovak Philharmonic, the Prague Symphony, East German tenor Peter Schreier (in collaboration with Dutch harpsichordist Ton Koopman), the Dresden Baroque Soloists and the Prague Chamber Opera. That on top of a lineup that ranged from American soprano Barbara Hendricks to the brilliant young Scandinavian trumpeter Hakan Hardenberger.

For if Americans in general have yet to discover Bad Kissingen - something one suspects contributes to the town's Old World air - the festival has not been slow to discover them. Not only have Lynn Harrell and Marilyn Horne figured on the artists' roster in recent years but this summer, at the June 23 opening, the Slovak Philharmonic was conducted by Lawrence Foster, followed on July 2 by Yoel Levi (with the Frankfurt Radio Orchestra) and on July 10 by Thomas Fulton (with the Munich Radio Orchestra).

Nor were the luminaries solely onstage. Also in attendance were Friedelind Wagner (grandaughter of Richard) and Goetz Friedrich, director of the Deutsche Oper, Berlin, who led a panel discussion on "Is It Still Meaningful to Compose Opera Today?" (Not surprisingly the consensus was that it was, although vociferous applause greeted the suggestion from one of the German critics that that did not include Philip Glass.)

This year we were the festival's guests for its final week, July 8-17, and without question the musical highlights were many and varied.

Despite a conspicuous lack of first-class voices, the Prague Chamber Opera offered a spirited "Cosi fan tutte," with an especially amusing Act 1 finale, and on the following night a real rarity, a semi-staged production of the oratorio "Abraham and Isaac" by the Czech composer Josef Myslivecek (1737-1781), a work that at the time of its Munich premiere excited the young Mozart's interest and admiration.

I say semi-staged, because here the solution was to take a group of static characters and literally turn them into statues, complete with pedestals, to be moved around stage for their various confrontations in the Biblical drama. That can't have been easy on the singers, most of whom had to remain frozen in place between arias. But the music itself made a lively impression, somewhere between Handel (e.g., the recitatives) and Mozart. Indeed, it is hard to think the latter was not influenced by Myslivecek's treatment of the Angel, with her two coloratura arias, when he later came to create the Queen of the Night.

More conventional operatic fare came via Hendricks and tenor Luca Canonici in a July 10 concert of arias, duets and overtures with the Munich Radio Orchestra in the Grosser Kursaal - a hall that, as one observer noted, seems almost like a wood-paneled version of the Musikvereinsaal in Vienna.

Once again Hendricks' soprano emerged as one of the wonders of the age, achieving some supremely lyrical effects seemingly without effort. Witness her gorgeous shading of the "Louise" and "Manon" excerpts (including some melting turns in the Gavotte from the latter). Canonici, by contrast, tended to bawl a bit at the outset but later, especially in "O soave fanciulla" from "La Boheme," his Corelli-like passion was tempered by a welcome sensitivity and tenderness.

For my money the Munich Radio Orchestra is a long way from even most second-rank American orchestras in matters of ensemble and intonation - something European audiences do not seem to mind - a comment that applies even more to the Prague Symphony. At least the first brought a relaxed cultivation to its work, whereas the second, under Jiri Belohlavek, even on such thrice-familiar ground as the "New World" Symphony displayed more brashness than precision. (For what it's worth, that isn't the way the Czech Philharmonic plays it.)

Nor does the Moscow Chamber Academy, for all its energy, appear to have more than a nodding acquaintance with baroque style. (Haven't they even heard recordings of this music by more stylistically aware groups?) Thus, although double-dotted and duly ornamented, their Telemann was more notable for its romantic phrasing and heavily slurred articulation.

Against that came the two concerts that crowned the weekend of July 15-17, an all-baroque program with Schreier and Koopman that, with few exceptions, could have stood as a model for the performance of Bach and Handel, and a mostly baroque program featuring Hardenberg and the Dresden Baroque Soloists that was not far behind.

Certainly Koopman understands this music, whatever liberties he may take. And although Schreier's tenor has never seemed ideally open, his superb projection of the text (with an almost Fischer-Dieskau-type penetration in places) actually seemed to give him an increased freedom up above as the evening progressed, without diminishing his attention to detail.

With his bright, pure tone, Hardenberg likewise impresses me as one of the outstanding artists of his generation. Here that was most evident in the Henze Sonatine, stabbing the air with its artful dissonances. But no less skilled was his work in the so-called Albrechtsberger Concertino, even if his controlled trumpeting did not quite succeed in turning musical dross into gold.

As for Richter, the legendary Russian pianist had not been on the schedule orginally, but once his coming was announced tickets proved as hard to get as if it were a Horowitz recital (he plays about as often these days).

At 74, he is considerably older now than when I first heard him (on his first American tour, in 1960) but just as unsmiling and still able to surprise. Back then he did it by stopping midway through a Haydn sonata and restarting, only to stop again and, with a sickening crunch, tear the lid from the keyboard and hurl it offstage. This time, by contrast, he had the hall darkened except for a single lamp shining on the music (from which he played throughout), lending the whole a curiously intimate air, as though we were eavesdropping on a late-night study session.

This time he began with Brahms, the C major Sonata, more willful than I remember in the past and a shade more brittle. Still, the introspective passages compelled, and by the time he reached the Finale (here launched into precipitously) one was reminded of the old power.

Even more potent was his Chopin, a selection of the Etudes in which every line was so clear as to have an almost independent existence. Yet each was always integrated in terms of tempo and color, giving something like the Op. 10, No. 12, an unaccustomed strength, however linear.

Born in 1918, Austrian pianist Erik Werba is barely his junior, yet he was also on hand, as accompanist to soprano Elisabeth Maria Wachutka in a Sunday-morning recital whose chief attraction, other than the interpretive flair the singer brought to a group of Wolf Lieder, was the German premiere of Czech composer Jiri Gemrot's "Five Lyric Songs on Poems of Ingeborg Bachmann."

Lyric they are, but there is also a gray haze hanging over these pieces, so that even the most affecting betrays an ominous undercurrent. Darkly dramatic, their debt to Janacek is obvious without seeming derivative, making for a series of concentrated mood pieces whose maturity belies the composer's 31 years.

On the other hand, who would have expected the musicians of the Semper-House-Band - a jazz ensemble drawn from the illustrious Dresden Staatskapelle - to have the Dixieland idiom down pat, as they demonstrated before an enthusiastic audience outside Castle Aschach the night of July 11? Topped by the throaty bass of Gunther Emmerlich (and a superhot clarinet), they served up everything from the Overture to the "Royal Fireworks Music" to "Alexander's Ragtime Band" (auf Englisch) with a hearty blend of verve and good humor.

I won't pretend to have gotten all the East/West jokes (of which there were more than a few - all in German), but the music came through loud and clear.

And next year's schedule? So far it includes cellists Lynn Harrell and Heinrich Schiff, pianists Vladimir Ashkenazy and Andre Gavrilov, violinist Dmitri Sitkovetsky and, among the singers, soprano Lucia Popp and tenor Rene Kollo, with return visits by the Dresden Baroque Soloists and the Prague Symphony. And, given the festival's record this summer, who knows what surprises?