The frequency of A4 is 440 Hz. This specific pitch is widely recognized as the standard for musical tuning, often referred to as "concert pitch."
Understanding A4 and its Significance
A4, also known as A440, is a fundamental reference point in Western music. Its frequency of 440 Hertz (Hz) means that the sound wave vibrates 440 times per second. This standard was officially adopted in 1939 by an international conference and later reaffirmed by the International Organization for Standardization (ISO) in 1955 as ISO 16.
This standardization ensures that musical instruments and ensembles can tune to a consistent pitch, facilitating harmonious performances across different musicians and instruments. While some orchestras or historical performance groups might use slightly different tunings (e.g., A=432 Hz or A=442 Hz), A440 remains the most prevalent standard globally.
Common Music Note Frequencies Around A4
To provide context, here's a table showing the frequencies of notes around A4, based on the standard A440 tuning:
| Note | Frequency (Hz) |
|---|---|
| G#4 - Ab4 | 415.3 |
| A4 | 440 |
| A#4 - Bb4 | 466.16 |
| B4 | 493.88 |
Note: These frequencies are based on the equal temperament tuning system, which is the most common tuning system used in Western music today.
Practical Implications
- Tuning Instruments: Musicians frequently use electronic tuners or pitch forks that are calibrated to A440 to ensure their instruments are in tune. Orchestras often tune to the oboe, which plays A4, or use a digital tuner displaying the precise frequency.
- Music Production: In music production and synthesis, setting the correct base frequency for synthesizers or samples often defaults to A4 at 440 Hz to maintain compatibility and pitch accuracy within a composition.
- Global Consistency: The adoption of A440 as a standard helps in the global consistency of musical performances and recordings, allowing music created anywhere to be played accurately worldwide.
For more detailed information on fundamental frequencies of music notes, you can refer to resources like Songstuff's article on Music Note Fundamental Frequencies.
