Concert pitch is a standard tuning reference used by musicians to ensure that instruments are in harmony. The most common concert pitch is the note A4, which is tuned to a frequency of 440 Hz. This means that when an instrument plays the note A4, it vibrates at 440 cycles per second, providing a consistent reference for tuning other instruments. In orchestras and bands, concert pitch helps musicians play together in tune. Instruments like the piano and violin are typically tuned to concert pitch, while others, like the trumpet or clarinet, may be transposing instruments. This means they sound different pitches than written, requiring adjustments to align with concert pitch.