Okay, I found some more information and a few new locations about the music sirens.
Starting off, there were 197 music sirens in Japan, including Generation 1 and 2 sirens. 2 sirens are across seas in Taiwan and another in the Philippines.
It also turns out that the Iga City Hall music siren was installed in 1984... meaning that the siren is actually still pretty new.
I have some information about the sirens and how many sirens are located at what locations.
Generation 1 sirens
Municipality offices: 64 sirens (Iga Ueno City Hall, Ueno Chamber of Commence and Industry, Mazayaki City Hall)
Factories: 45 sirens (excluding YAMAHA)
Stores: 27 sirens (Marumitsu Department Store Sendai, TOKIWA Main Store
Schools: 25 sirens (Mazayaki University)
Bank-related: 19 sirens (Tajimi Shinkin Bank)
Other: 4 sirens (Taiwan, Philippines)
Generation 2 sirens
Municipal Offices: 6 sirens (Okayama Prefectural Office, Kishiwada City Hall)
Factories: 2 (YAMAHA)
Schools: 3 (Yawatahama, Tenri Pool*2 units*)
Other: 1 (Uwajima Castle)
Ueno Chamber of Commence and Industry siren
Only a short walk from the city hall to this siren, the siren contains only 4 tones and was installed BEFORE the city hall installed their siren.
I believe this siren was installed to play the Westminster chimes, considering the song only contains 4 notes.
Himeji Chamber of Commence siren
Unfortunately, no close-up photo of the siren, and the building seems to be have been removed or redone.
3 times a day at 7 AM, 1 PM and 10 PM, the siren plays "Home Road" by Dvorak.
Ogamiyama Park siren
In the mountains surrounding Amami city (formerly Naze City), a siren once stood. Unfortunately, the electricity supplied to the island was not enough for the siren to operate properly. At times, the rotors would stop spinning entirely or fail to activate. The siren would play the last song in 1969.
The siren would play Blowing Spring Breeze at 6 AM, Home! Sweet Home! at 12 PM, Home Road at 5 PM and Brahms Lullaby at 10 PM.
There were 2 sirens in the city. One was located within the city and the other at the Mazayaki University(the first unit ever sold and shipped).
Unfortunately none of the sirens had a close-up picture.
Sapporo City Hall siren
Somewhere in town sits or once sat a music siren, playing music to the locals. Yet again, no close-up photos.
There are 2 articles that cover 2 sirens...
One siren is or was located atop the City Hall, the other siren on a store named "Marushin".
There is a third page where someone asked about the music in the city, in which I have no idea if this is the same siren or there's two sirens.
That's just a short bit of information I wanted to add. Just a good... 176 more sirens to locate. We have made a dent in the siren count.