# Concert pitch

Source: https://arcosounds.com/glossary/concert-pitch
Also known as: A440, tuning standard

**Concert pitch is the agreed tuning reference for an ensemble, standardly the A above middle C at 440 Hz, though many orchestras tune to 442 Hz.**

A440 was adopted as an international standard in 1939 and remains the default for solo practice, tuners, and most recordings. In practice, many European orchestras tune to 442 or 443 Hz for a brighter sound, and historically informed ensembles playing baroque repertoire commonly use 415 Hz, roughly a half step lower.

For a string player the practical consequence is that the tuning reference must match the room. Practising at 440 and arriving at a rehearsal tuned to 442 puts every open string slightly flat against the ensemble. Arco's tuner supports 440, 442, and 415 for this reason.

The term also distinguishes sounding pitch from written pitch for transposing instruments, a written C on a B flat clarinet sounds a B flat at concert pitch.

Canonical source: https://arcosounds.com/glossary/concert-pitch