Strings, strings, and more strings were the order of the evening as the Institute of Musical Tradition closed out its 2008 Fall Season with a Scandinavian Christmas concert tonight in Rockville.  Before a full house of Swedes and Norwegians (or so it seemed), Andrea Hoag, Loretta Kelley, and Charlie Pilzer were joined by Bruce Sager for a night of polskas, waltzes, walking tunes, and other music from the north.  The evening opened with triple fiddles backed by Pilzer’s steady bass, and throughout the night the four musicians played wonderful music as soloists, duets, trios, and a quartet. The dance polskas (not to be confused with polkas) were great fun, but I especially enjoyed the walking tunes such as Solskenslaten (The Sunshine Tune) and The Bell Tune, where the bells on the reins of the bride’s  horse were tuned with the fiddle to ring in harmony as the fiddler led a traditional wedding procession. Loretta Kelly (left in the photo above) played two different hardingfeles (or Hardanger fiddles) with their sympathetic vibrating strings, while an energetic Bruce …