+"440" commonly designates a specific audio [frequency](/wiki/frequency) of 440 cycles per second. This value, often termed A440, is the modern standard for musical [pitch](/wiki/pitch) worldwide. It serves as a universal reference for instrument tuning.
+## See also
+- [Music](/wiki/music)
+- [Tuning](/wiki/tuning)
+- [Concert Pitch](/wiki/concert_pitch)
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