In an orchestra, the concertmaster is the leader of the first violin section. There is another violin section, the second violins, led by the principal second violin. Any violin solo in an orchestral work is played by the concertmaster (except in the case of a concerto, in which case a guest soloist usually plays). It is usually required that the concertmaster be the most skilled musician in the section, experienced at learning music quickly, counting rests accurately and leading the rest of the string section by their playing and bow gestures.