The Leader or Concertmaster plays a crucial in any orchestra. After the conductor, he or she is the most important person in the ensemble.
They lead the first violins and sit just to the conductor's left in the seat closest to the audience. They are responsible for tuning the orchestra before the conductor arrives on the platform.
The leader is usually judged to be the most gifted violinist in the orchestra, and any violin solo - apart from a concerto where there is a named soloist - is usually played by them.
The role also involves having the confidence and force of personality to "lead" the entire orchestra and speak for the group in rehearsals with the conductor. In the LSSO, the leader is usually one of the older players.