Fans of orchestral music are heading for the San Francisco Symphony this weekend, where Osmo Osmo Vänskä is set to lead the orchestra in the Mendelssohn Violin Concerto, a premiere by Thomas Larcher, one of a very few European composers who seem willing and able to reconcile modernism and traditional Romantic musical ideas, and to top it all off, Ralph Vaughan Williams' magnificent Symphony No. 2, the “London.” Alexander Barantschik is the soloist.