When the orchestra's rented score for Silvestrov's The Messenger showed errors during Saturday's rehearsal, Feltsman substituted Bach's Concerto No. 5 in F Minor, and played it on a day's notice. The switch was a boon to this imaginative program led by Mischa Santora, a feast of J.S. Bach and works related to Bach, including Villa-Lobos' gorgeous Bachianas Brasileiras No. 5 and Bartok's Divertimento for Strings.

The Russian-born pianist, one of the most fascinating artists on the American scene today, is a phenomenal technician, who played with a crisp, detached touch and had a penchant for "conducting" along with the conductor. He is also exceedingly musical; every line and phrase was illuminated, and his tasteful style in the two concertos (originally for harpsichord) made this one of the most memorable performances of the season.

Understandably, Feltsman used the music for the F Minor Concerto, which opened the program. It was a spirited, vibrant performance, though the orchestra's ensemble was a bit unsettled at times. The famous "Largo" at its center was beautifully phrased.

Bach's D Minor Concerto No. 1, which came next, was an extraordinary treat, and one that emphasized virtuosity and clarity. Tempos were brisk, and the pianist's pointed articulation crackled with vibrancy. Bach's cadenzas were brilliant flourishes, and the pianist added a few tasteful embellishments. The slow movement was lyrical, introspective and full of expression.

Feltsman and Santora communicated well, although I wished for more sound from the orchestra. Feltsman barely had time for bows, before running to catch a plane for a gig in New York's Carnegie Hall.

After intermission, Bach's Brandenburg Concerto No. 3 was warm and well paced.

The second half centerpiece was a string orchestra version of Villa-Lobos' Bachianas Brasileiras No. 5, originally scored for soprano and eight cellos. A rhapsodic duet by acting concertmaster Jennifer Roig-Francoli and principal cellist Benjamin Karp was a highlight. Although the orchestra had some rocky moments, the performance was both sensuous and wistful.

The afternoon's real discovery, though, was Bartok's Divertimento, which concluded. Santora gave the audience of about 200 a descriptive road map beforehand that enhanced the experience. Attuned to its many changing moods and characters, the conductor led its Hungarian folk melodies with spontaneity. The slow movement was mysterious and plaintive, followed by an exuberant finale, that the musicians attacked with intensity and flair.

Don't miss this one.

The concert repeats 7:30 p.m. today in Greaves Hall, Northern Kentucky University. Tickets: 723-1182.