# How was sound (note) frequency first measured? **URL:** \ **Category:** Factual Questions\ **Created:** [March 29, 2024, 8:21pm UTC](https://boards.straightdope.com/t/how-was-sound-note-frequency-first-measured/999578 "2024-03-29T20:21:02Z")\ **Posts on this page:** 5\ **Page:** 2
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [March 30, 2024, 2:20pm UTC](https://boards.straightdope.com/t/how-was-sound-note-frequency-first-measured/999578/21 "2024-03-30T14:20:01Z")
Many of us are missing the distinction between frequency standards and knowledge of what a frequency actually was. It’s an interesting point, because sometimes fields of science get pretty far along before their fundamental measurements are actually understood. For example, crystalline structure in terms of Angstroms, and astronomy in terms of Astronomical Units, could advance before the size of the Angstrom and the AU were known. “The Italian scientist, inventor, and experimentalist Galileo (1564-1642) drew a knife edge across the milled (or serrated) edge of a coin and noted the tone produced. He theorized sound to be a sequence of pulses in air. Sliding the knife more quickly produced higher tones, so he realized higher tones required a faster train of pulses.” > **[The History of Audio and Sound Measurement | Pro Audio Encyclopedia](http://proaudioencyclopedia.com/the-history-of-audio-and-sound-measurement/)** ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 30, 2024, 4:56pm UTC](https://boards.straightdope.com/t/how-was-sound-note-frequency-first-measured/999578/22 "2024-03-30T16:56:24Z")
> [@Napier](#): > > For example, crystalline structure in terms of Angstroms, and astronomy in terms of Astronomical Units, could advance before the size of the Angstrom and the AU were known. Certainly true of the AU, and also atomic mass units, but isn’t an angstrom defined as 10^-10 meters? ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [March 30, 2024, 5:17pm UTC](https://boards.straightdope.com/t/how-was-sound-note-frequency-first-measured/999578/23 "2024-03-30T17:17:13Z")
> [@pulykamell](#): > > With the chromaticism and upper chord extensions of harmonies, ET does make that stuff easier to deal with. I remember Jacob Collier posting this: [![](https://img.youtube.com/vi/mPZn4x3uOac/maxresdefault.jpg "In The Bleak Midwinter - Jacob Collier") ](https://www.youtube.com/watch?v=mPZn4x3uOac&t=245) ---
**Author:** ![Kedikat](https://avatars.discourse-cdn.com/v4/letter/k/ed655f/32.png) [@Kedikat](https://boards.straightdope.com/u/Kedikat)\ **Post date:** [March 30, 2024, 5:57pm UTC](https://boards.straightdope.com/t/how-was-sound-note-frequency-first-measured/999578/24 "2024-03-30T17:57:27Z")
These fellows created devices to produce sound by rotating discs. Mechanically linked, so the frequency of the rotation is known. Not actually measuring a frequency, but able to know what the frequency of the generated sound is. [https://americanhistory.si.edu/science/sirens.htm](https://americanhistory.si.edu/science/sirens.htm) ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [April 2, 2024, 12:40am UTC](https://boards.straightdope.com/t/how-was-sound-note-frequency-first-measured/999578/25 "2024-04-02T00:40:47Z")
> [@DPRK](#): > > Huh? The tuning fork was invented in the early 18th century, for starters, if we are talking about precisely reproducible audio frequency standards. I should have said recorded. [Previous page](https://boards.straightdope.com/t/how-was-sound-note-frequency-first-measured/999578.md?page=1)