關於 pitch hz ，我們在網路上蒐集到這些相關的討論、資訊與評價

▎Book Reading
　
「一直到1980年代，國際間對於標準音高才取得共識，也就是A=440 Hz。你可以在第一弦的第五格彈奏出這個440Hz的A。在這之前的300年間，標準音高變過好多次，從A=419Hz 到A=483Hz都有 (依據好音樂的科學中書中所提到的，標準音高還會有地區性，可能英國和法國的標準還會不同)。雖然現今大部分的音樂家都使用標準音高，但是澳洲吉他大師Tommy Emmanuel卻將他的吉他調成 A=444Hz，而傳奇爵士吉他手Martin Taylor則將他的吉他調成A=442Hz，兩者覺得這樣的調整可以增加他們樂器的"clarity和tone"」
- from The Acoustic Guitar Bible, Concert Pitch (P.17)
　
非常有趣的一段，不知道Tommy Emmanuel和Martin Taylor在哪幾張專輯真的有這樣調音高，真的沒有什麼仔細聽，不過至少他們在共同演出的時候應該是調成一樣的!
　
▎Martin Taylor 和Tommy一起合奏的"True"
https://youtu.be/mtWNcfFNy2s

Most music worldwide has been tuned to A=440 Hz since the International Standards Organization (ISO) promoted it in 1953. However, when looking at the vibratory nature of the universe, it’s possible that this pitch is disharmonious with the natural resonance of nature and may generate negative effects on human behaviour and consciousness.

Some theories, although just theories, even suggest that the nazi regime has been in favor of adopting this pitch as standard after conducting scientific researches to determine which range of frequencies best induce fear and aggression. Whether or not the conspiracy is factual, interesting studies and observations have pointed towards the benefits of tuning music to A=432 Hz instead.