John Calhoun Deagan, born in 1853, was blessed — or cursed — with a “golden ear.” Early in his musical career, he played clarinet in an orchestra that also included an out-of-tune glockenspiel. No one else seemed bothered, assuming that was how glockenspiels are supposed to sound, but J.C. Deagan was irritated every time it was used. J.C smuggled the instrument home, removed some metal from the offending bells and returned the glockenspiel. Word got around that J.C. could improve the sound of glockenspiels, then grandfather clock chimes. Eventually it became J.C. Deagan's full time enterprise to manufacture improved glockenspiels, xylophones and marimbas. He set up shop in Chicago in 1897 as J.C. Deagan Musical Bells.

As the 19th Century turned to the 20th, European style carillons were being imported to North America. When J.C. heard them, his “golden ear” was again offended. He was convinced the traditional bell shape would never be suited for musical performances. J.C. tried other shapes and settled on bronze tubes that would be able to project the sound levels of traditional bells, but with more musically pleasing harmonic tones.

J.C. Deagan continued to innovate with his chimes. Borrowing technology from the rapidly growing telephone industry, J.C. powered his electric strikers with 48 Volt DC generators turned by an AC motor. Initially, his instruments were only playable from an electric keyboard, but soon J.C. would adapt grandfather clock style mechanisms to automatically ring the time. Ultimately an automatic music roll player, similar to those used on self-playing pianos, added musical concerts to the daily ringing schedule. Another notable innovation was a system of electric dampers that prevented notes from overlapping while playing the chimes.

J.C. Deagan was a staunch supporter of using pitch A=440 as the universal standard. Earlier in his career, he produced his percussion instruments tuned to the different pitch standards used in orchestras around the world. Eventually the Deagan Company only produced instruments at A=440 reducing the challenge of building and storing multiple pitches of instruments. Deagan Tower Chimes were made in both A=435 and A=440 pitches. The pitch of any given Chime can be found stamped on the A-note chime tube.

After J.C. Deagan's passing in 1934, company engineer Henry Schluter continued his work, introducing the patented Harmonic Quintamonic Tuning of the chimes in 1939 at the New York World’s Fair. J.C. Deagan's original tubular chimes, tuned by simply trimming their length, only allowed single note melodies to be played. The harmonic tuning allowed chords, both major and minor, to be performed on the chimes. The new harmonically tuned chimes are easily recognized by their scalloped, rather than straight, outer surfaces. With harmonic tuning, the damping mechanisms invented by J.C. Deagan were used to prevent the many long decaying tones from building up into a cacophonous roar.

The J.C. Deagan Company built more than 440 Tower Chime instruments between 1917 and 1958. The systems ranged from 1 to 97 chimes; 10 and 16 note chimes were the most common sizes. Approximately 300 Deagan Tower Chimes remain in existence, more than a third of which are still ringing today.