The trio Time for Three got its start when its members were students at the Curtis Institute in Philadelphia and discovered that they had a common interest in bluegrass and country fiddling. One appealing point of Letters for the Future is that the composers involved, Kevin Puts and especially Jennifer Higdon (a Tennessee native familiar with bluegrass), retain that influence lightly in their virtuoso concertos, offered here. But as Time for Three has evolved, the group has thrived primarily on its collaborations with other musicians. The combination of two violins and double bass proves to be a protean grouping that can by turns evoke jazz, virtuoso classical music, Americana, and more. Here, Time for Three performs works that evoke the Classical-era symphonie concertante tradition, with Time for Three as a solo group set against the Philadelphia Orchestra under the baton of Xian Zhang. Puts and Higdon weave quite a few styles into the combination. Higdon's Concerto 4-3, although it contains a stronger bluegrass element, also has an admixture of jazz executed by the bassist, Ranaan Meyer. Both concertos have lyrical slow movements that ought to be solid crowd-pleasers but do not cloy. What's most satisfying is the sense that both the composers and the performers have been stretched a bit by the encounter, effectively recorded over two days by Deutsche Grammophon at Philadelphia's Verizon Hall. This is, in its way, a fresh development in the composer-performer relationship. ~ James Manheim