What does A440 mean in music?

Musical term that refers to the pitch A above Middle C having a frequency of 440 Hz, or cycles per second. This is sometimes referred to as “cconcert pitch.” Following the principles of equal temperament, A440 means that the C above it has a frequency of approximately 523.3Hz.

When was the A440 invented?

Johann Heinrich Scheibler recommended A440 as a standard in 1834 after inventing the "tonometer" to measure pitch, and it was approved by the Society of German Natural Scientists and Physicians at a meeting in Stuttgart the same year.

What is 440 steel?

When strengthened using this process, 440 steels are the hardest of all the stainless steels, making them both abrasion-resistant as well as corrosion-resistant. When in its soft “annealed” state, 440 steel is easily worked, machined, and manipulated into shape, where it can then be hardened and gain the increased strength for which it is known.

Why is A440 a hexadecimal?

It is designated A4 in scientific pitch notation because it occurs in the octave that starts with the fourth C key on a standard 88-key piano keyboard. On MIDI, A440 is note 69 (0x45 hexadecimal ). An 88-key piano, with the octaves numbered and middle C (cyan) and A4 (yellow) highlighted.