The Wednesday evening concert at Carol Woods Retirement Community featured three members of the Isosceles Ensemble in a performance of Mozart’s Divertimento for String Trio, K. 563 and a solo performance by Elizabeth Phelps, principal second violin of the North Carolina Symphony.

Phelps chose this occasion for her first public performance of one of the most challenging of compositions for solo violin: Sonata No. 4 in E minor, Op. 27, by the Belgium born, Eugène Ysaÿe. Legend has it that he composed his set of six sonatas for solo violin in a very short time after hearing a performance of the complete works for solo violin by J. S. Bach. Each one is dedicated to a different renowned violinist of the time. Number 4 was dedicated to Fritz Kreisler who was known for his smooth long-bow approach and elegant left-hand finger work.

Before launching into the Ysaÿe Sonata, Phelps played brief samples of the music that inspired it: an Allemande, a Sarabande, and a Presto from the Bach partitas and sonatas. The first movement, “Allemande. Lento maestoso” was most impressive with its extended double-stop accompaniment and counterpoint. If you closed your eyes, you would surely have believed two violinists were playing.

The second movement, “Sarabande. Quasi lento” was introduced by a pizzicato statement, followed by a sad, but beautiful melody and more of that incredible double-stop technic. The movement ends with a brief ethereal harmonics passage and closing with a partial restatement of the opening pizzicato theme.

The third movement, “Finale. Presto ma non troppo” was a dazzling display of fingering technique based on thematic material that was reminiscent of a gigue. Phelps demonstrated impressive technic and interpretive sensibility. This is a gem that will be heard with enthusiasm at all her future performances of it.

For the next work on the program Phelps was joined by violist Samuel Gold and cellist Nathaniel Yaffe: both North Carolina Symphony musicians.

Despite the title, Mozart’s Divertimento for String Trio, K. 563, is no light diversionary piece. The first two movements are in sonata form with thematic statement and development – one in 4/4 and one in 3/4. One in the tonic key (B-flat) and one in the sub-dominant key (A-flat). Thus throughout the piece, Mozart varies keys and tempos to keep the listener’s attention.

There are two minuettos (movements 3 and 5) of differing structure. The fourth movement is a theme and variations of exquisite charm, and the closing movement is a rondo. Add to all this structural wisdom the richness of Mozart’s thematic material, and what you have is pure delight.

It was clear that these fine musicians had played this sparkling piece before and that they took much pleasure in performing it again on this occasion. And the audience loved it, judging by their enthusiastic applause.