first violin

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun music The lead or primary violin role in an orchestra or other ensemble, or in a musical composition, that typically contains the melody and is often more technically demanding than the second violin role. The first violin role is played by a first violinist, typically the best violinist in the orchestra.
• noun UK (music) The leader of the violin section of a symphony orchestra; the concertmaster.