WALTER PISTON '24 stood up Friday and received an ovation for his Symphony No. 6 (1955), performed in honor of his 80th birthday. Written to celebrate the 75th season of the Boston Symphony Orchestra, the symphony bridges the gap between two groups of modern composers: the conservatives like Copland, MacDowell and Gershwin on one side, and the adventurers like Stravinsky, Ives and Cage on the other. Piston's music contains smatterings of new tonal techniques, and his rhythmic and melodic lines are original, not derived from folktunes, but he's interested above all in restoring order and clarity to music.

Of the four movements in Piston's symphony, the second is the most striking. Its rush of rhythms could easily and excusably lead to a disastrous performance. But the extraordinary direction of James Yannatos prompted well-coordinated playing, particularly from the strings and percussions. In the third movement two soloists, David Commanday on cello and Margot Wyckoff on flute, gave especially fine performances.

Yannatos's conducting technique is excellent, and his orchestra responds well to him. But four rehearsals is barely enough time to prepare for an entire concert, so the rest of the evening didn't match the Piston. Beethoven's Second Symphony, first on the program, sometimes dragged during its second and third movements, and generally sounded less inspired than other HRO performances of Beethoven. Some extra rehearsing could have polished away the rough spots in both the tutti and solo sections.

Friday night's guest soloist was Richard Kogan, winner of the 1974 HRO Concerto Competition. Kogan is a 19-year-old freshman who upon arrival last fall was immediately welcomed in musical circles as the most accomplished pianist at Harvard in many years. He has studied piano since age seven with Nadia Reisenberg in New York City and with Nadia Boulanger last summer in France, and his performance of the Liszt E Flat Piano Concerto was exceptional. This is as it should be--one of the greatest virtuoso pianists who ever lived, Liszt was fond of composing fiery technical showpieces. Kogan's fingers glided effortlessly across the keys in the scale passages, his chords were clean and full-toned, and Liszt's famous accelerating octave chromatic scales sent tense waves of excitement through the audience. Kogan's marvelously smooth execution of Liszt's flamboyance was accompanied by a sensitive, mature interpretation of the melodic lines, which often teeter precariously on the brink of ridiculous melodrama and so are salvageable only through extreme delicacy.