conˈcertmaster noun (N American or as a translation of Ger Konzertmeister)

The leader of an orchestra

concerto grosso noun (pl concerti grossi)

1. A musical work in which solo parts are played by a small group of instruments, usu alternating with strings or an orchestra
2. The main body of instruments in such a work

concert overture noun

A piece of music like an overture, but composed specially to be played at a concert

concert party noun

1. A small group of performers, entertainers, etc, often at a private function
2. A group of people working together to buy shares separately, in order to use them later as one holding (stock exchange sl)

concert pitch noun

1. A standard of pitch that has varied considerably during musical history, but is now internationally standardized so that A above middle C has a frequency of 440 hertz (see international (concert) pitch under international, French pitch under French)
2. A high state of readiness, tension, etc

in concert

1. Working or conspiring together
2. Performing at a concert venue