(Oh my favorite musical subject)
Sadly, this is only true sometimes. 😔
They changed the frequency, as old bells cracked or were melted down for cannons or whatever it is they melt church bells down for, they slid the scale a couple hertz. Many bells are digital, and play on an A = 440hz scale. There’s a church near me where the treble bells are digital, and the bass bells are one of the old frequency. They play them at the same time, in the same song. The discord is anything but healing.
Frequencies are intriguing to me. Being a violin player, I have some inside baseball on them. When A = 444hz, you get the god frequency or solfeggio tone (528hz) when a C is played. Some erroneously claim that music was tuned this way before 1800. This is simply not true, as gut and even steel strings are at their limit when tuned to a 440A. Midevil, Renaissance, Baroque or early Classical music was always tuned to A=338 or below. The violin was modernized in 1790-1810; the entire structure was changed to accommodate 440A, which is higher tension and can be louder. The strings were modernized at the same time, often with a brass or steel string for the high E note. This results in a 695hz E string, which is the upper limit of engineering for brass and steel wire. So no, the music of old was not played in 444, except for before the violin was invented and needed. Since its inception, the violin was played liturgically, and it was played at 338A or a lower scale.
There’s also Mtns In The Sea and Rabbai David Louis to listen to. They concentrate on ancient scales and tones, and while I think they may not be super historically accurate it is super soothing to listen to those scales.