Adolf Sax may have been thoroughly German, but the instrument for which he is best known and that bears his name has peculiar charms that are best realized in French music and in jazz. Why this should be so probably has something to do with the saxophone's nasal reediness that mirrors the sound of the French language, and with its almost vocal suggestiveness that is a marvelous vehicle for the sophistication of so much jazz.

The instrument's best features were strikingly displayed at the University of Maryland's Tawes Theatre Wednesday night in a recital given jointly by Donald Sinta, who is on the faculty of the University of Michigan, and by Jean-Marie Londeix, who teaches at the National Conservatory of Bordeaux. The occasion was the second concert of this year's World Saxophone Congress in progress at the University of Maryland, and the hall was full of saxophone-carrying enthusiasts from all over the world.

Sinta, whose playing is characterized by spontaneity and daring, was at his best in a convincing transcription of the Poulenc Oboe Sonata and in a delightful short piece by Steve Galante, "Sax Sounds III: Diminishing Returns," for two amplified saxes. Sinta was joined in this by Tim Miller, who did a splendid job with the subtle metamorphosis of an ostinato into both rhythmic and percussive changes. The piece is full of terrific sound effects that Sinta handled with great panache.

Londeix's idiom, on the other hand, is subtle and carefully controlled. His performance of a transcription of the Bach Suite No. 1 for Unaccompanied Violin was brilliant even if the baroque in general and Bach in particular do not translate happily into saxophone. But his careful unraveling of "Prelude, Cadence et Finale" by Alfred Desenclos was a lovely lesson in musicianly performance and in the considerable virtues of his instrument.