Most local music fans know James Sommerville as the Boston Symphony Orchestra’s superb principal horn. But he has another musical career: Sommerville has been music director of the Hamilton Philharmonic Orchestra (in Ontario) since 2007 and is a frequent guest conductor with other orchestras in his native Canada.

Now Sommerville is set for his first full concert on a Boston podium. He will lead New England Conservatory’s Youth Philharmonic Orchestra on Feb. 12, in a program that includes Jennifer Higdon’s “blue cathedral,” Ravel’s G major Piano Concerto (with soloist Hannah Byun, a senior at the Walnut Hill School), and Mussorgsky’s “Pictures at an Exhibition.” Sommerville replaces BSO assistant conductor Marcelo Lehninger, who withdrew from the engagement because of a scheduling conflict. (Interestingly, Lehninger led a Hamilton Philharmonic concert in November that included the Ravel concerto.)