A440 Pitch Standard

International standard pitch tuning fundamental frequency of 440 Hz (ISO 16).

Core Principles & Analysis

• Codified as international standard concert pitch by ISO 16, first issued in 1955.
• Corresponds to the A above middle C, the note orchestras tune to before a performance.
• Historical concert pitch varied widely, from around 415 Hz in Baroque ensembles to above 450 Hz in the 19th century.

Specifications & Metrics

• FREQUENCY: 440 Hz