CLASSICAL | 'Scordatura Violin' 

If you're a violinist, sometimes a composer wants you to play out of tune — or more precisely, to deliberately retune your strings. "Scordatura," as this technique is called, is generally done to increase the tone color and expressive range of the instrument, adding low or high notes beyond its normal compass. Scordatura has been used for several centuries; if you caught the RPO's Mahler Fourth last week, you heard a scordatura violin in the second movement. Its great day was in the Baroque era, however, and the members of Publick Musick give a lesson in scordatura tomorrow night at the Memorial Art Gallery. The group will play works by Schmelzer, Kindermann, and two of Heinrich Biber's "Mystery" Sonatas, the most famous of scordatura violin works, written in the 1670's.

Publick Musick's "Scordatura Violin" takes place Thursday, March 15, at the Memorial Art Gallery's Fountain Court (500 University Avenue). 7:30 p.m. Included with MAG admission, which is half-price after 5 p.m. on Thursdays. 276-8900; publickmusick.org.