After intermission came the new Williams work, a well-crafted two-movement concerto that clearly fulfills its stated aims of paying tribute to Pilot and showcasing her formidable musicianship. That said, it is a modest work in its musical substance and in its effect. The first movement, titled “On Willows’’ after a line from Psalm 137, is slow, spare, and ruminative, with an undulating solo harp line drifting above a hazy orchestral landscape, creating a kind of spectral chamber music that seems to be heading somewhere it never quite reaches. The second movement, “On Birches’’ after the Robert Frost poem, is more chipper, caffeinated, and rhythmically emphatic, with an extended cadenza that puts the soloist’s virtuosity squarely on display.
And Pilot had plenty of it to show this appreciative audience. Her playing had impressive rhythmic clarity but also a keen sense of mood and color, not to mention a fundamental graciousness and expressive warmth. As the crowd’s ovation made clear, she will be missed.
