Admirers of Jean-Pierre Rampal's brand of flute playing got two for the price of one last night at the Kennedy Center. There was the great French musician. But there also was his former pupil, now a colleague in arms, Andras Adorjan, an artist of rank that sounded equal to that of his former master.

In the delights of the opening "Recreation for Music," by Leclair, the two musicians sounded unison notes that were not only one in pitch but one in texture and quality of tone. Adorjan quickly showed in the Ballade by Frank Martin, that his art, like that of any great musician, is his own. His attack has a welcome incisiveness, his tone the light and shade that mark a true master. He is a product not only of Rampal but also of Aurele Nicolei, a master of another cast.

When the two joined forces in a trio sonad by Bach, their feeling for style made cadential trills occasions for special joy while their phrasing often created the effect that two flutes were under a single control. There were febcities of playing in a trio by Kuhlau, it not enough to keep the music from sounding somewhat empty-headed.

To Schubert's Variations on his song, "Trock'ne Blumen," Rampal brought every beauty of sound and line imaginable. If you have perhaps thought that the Doppler effect was a remarkable phenomenon, you should have heard the evening's finale, a fantasy on melodies from Verdi's "Rigoletto," by the brothers Doppler, Franz and Karl. Fireworks all over the place, dazzlingly discharged by both flutists, with the kind of assistance from John Steele Ritter at the piano that he gave throughout the evening from both piano and harpsichord.