Here is a checklist with things a concertmaster needs to take care of.
– He is the leader of the first violin section.
– He is the leader of the orchestra.
– He is the first solo violinist and has to perform all concertmaster soli. Sometimes he’ll perform as a soloist.
– He is the intermediary/contact between the orchestra and the conductor.
– He has to lead group or string rehearsals.
– He is responsible for the bowings while keeping the desired articulation in mind, or he needs to translate the desired articulation into the right bowings.
– He has to lead in a physical way and has to be able to show his intentions with movements and body language.
– In case someone doesn’t perform well, he needs to speak with this person in order to get him back on track.
– He has to create social cohesion if necessary.
– In amateur orchestras: he has to help others to play well.
– Maybe only in amateur orchestras: he has to support the players mentally.
Several leadership styles could be used in order to achieve these things.