This violinist's pristine intonation and rhythmic verve make her a natural in the world of Baroque pieces by Bach and Vivaldi. But Beyer is also game for unique challenges, such as playing an instrumental part normally assigned to a vocalist in Monteverdi's Scherzi musicali. Her singing tone gives performances of Corelli and Couperin a memorable effervescence. And in her role as leader of the ensemble Gli Incogniti, she's a conducting force to be reckoned with.