Guitarist Christopher Parkening made two changes in his programThursday night at the Kennedy Center, and both were substantial improvements. Instead of Mauro Giuliani's Variations on a Theme of Handel, he played Fernando Sor's Variations on a Theme of Mozart, dedicating it to the memory of his late mentor, Andre's Segovia.

The change was highly appropriate. Sor's name is the most important in the history of guitar before Segovia; he had been absent from the program until this substitution, and his chastely classical Mozart Variations -- cool, understated and finely proportioned -- provided just the right touch of contrast in an evening primarily and brilliantly dedicated to samples of Iberian ethnic styles. It was the kind of music Segovia would have played, and Parkening's crisp, graceful interpretation was very much in his mentor's spirit. It was also technically better than Segovia could have managed, at least in recent years.

The other substitution was a two-guitar arrangement of the intermezzo from "Goyescas" by Enrique Granados, with guitarist David Brandon joining Parkening and staying on for the last quarter of the program. Like the Miller's Dance from Falla's "Three Cornered Hat," which they played as an encore, the Granados intermezzo involves vivid orchestral imitations of guitar sounds. When the music is transferred to guitars, there is almost a sense of homecoming in the event -- particularly when the guitars are played so flawlessly. Other dazzling two-guitar items included Rodrigo's loving setting of the old Spanish song "De los alamos vengo," and a sprightly arrangement of the old English song, "Watkin's Ale."

On his own, Parkening played several pieces by Bach -- immaculately, except for a couple of smudged notes in "Jesu, Joy of Man's Desiring" -- and a wealth of works by such composers as Albeniz, Torrijos, Sanz, Torroba and Villa-Lobos, where the vitality of folk-dance rhythms was often the chief attraction. Parkening is a fine exponent of that vitality, with a technique that ripples out the notes effortlessly. His solo playing was a delight, and the duets, expanding the available repertoire and enriching the sound, were in some ways even better