National Philharmonic's strings deliver ebullient warmth

Even pared down to chamber proportions, the National Philharmonic strings can muster impressive warmth and breadth. Their program at the Music Center at Strathmore, in North Bethesda, on Saturday opened with Sibelius's three-movement suite, "Rakastava" ("The Lover"), and ended with the Tchaikovsky Serenade for String Orchestra, Op. 48. In both, a cello section of just four players produced impassioned expanses of gorgeous color while the upper strings, sounding clean and transparent, floated abo...