From the Gretsch Guitars Website:
Among their many distinctive features, Gretsch electric guitars have been known for decades for a variety of highly individual bridge designs. The history of these bridges is as colorful and interesting as the Gretsch instruments they’re part of, and many of the original-era designs live on today in modernized form.
Today’s four most prevalent bridge types for Gretsch electric guitars and basses are the Adjusto-Matic™, Space Control™, Rocking Bar and Synchro-Sonic™ bridges. There are other types here and there, but those are the big four. Here, in chronological order, is a look at each one:
Introduced on Gretsch guitars in 1951, the Synchro-Sonic bridge was a welcome innovation in that it was one of the first guitar bridges—if not the very first—to feature independent intonation adjustment for each string (it preceded the Gibson Tune-O-Matic bridge by about a year).
Back in the early 1950s, it was originally named the “Melita” Synchro-Sonic after its designer, Sebastiano “Johnny” Melita, who built the distinctive-looking bridges for Gretsch in his own workshop. The Synchro-Sonic’s elaborate design is described in 50 Years of Gretsch Electrics as a “complex mass of chrome-plated metal that looks like it might be more at home on a saxophone.” Nonetheless, the book continues, “Gretsch immediately realized the Melita’s potential to provide the more accurate intonation that was required on electric guitars.”
Such accurate intonation is enabled by a sliding saddle for each string that can easily be moved forward and backward. Each saddle is topped by a thumbscrew that is easily loosened to allow saddle adjustment and then tightened to lock the saddle in place. No tools are required; all adjustment can be made using only the fingers. The Melita Synchro-Sonic bridge was largely superseded in the late 1950s by the simpler Space Control bridge (see below), but was revived in Gretsch’s modern era as a classic feature and remains in use today on several Falcon™, Country Club™, Jet™ and Penguin™ models.
“Rocking” Bar Bridge
Fixed solid-bar bridges were common on early Gretsch guitars; these were simple chrome-, nickel- or gold-plated brass bars seated on ebony or rosewood bases, with the entire assembly held in place only by string tension. There were no light-gauge electric guitar strings in the 1950s, and while the design straightforwardness of these bridges offered good sustain and tone, there was no means of adjusting individual string intonation (other than the entire bridge being positioned at an angle).
With impetus and input from Chet Atkins, Gretsch developed a new design for these bar bridges in the mid-1950s that featured cone-shaped postholes. This allowed the bar to smoothly rock back and forth on guitars fitted with Bigsby® vibrato tailpieces while still offering solid sustain and great tone. These “Rocking” Bar bridges became a hit with players and have been a Gretsch staple ever since.
While only a very few Gretsch guitar models use a vintage-style non-rocking bar bridge today (i.e., the G6120EC Eddie Cochran Tribute Hollow Body and G6120DSW Chet Atkins Hollow Body), the modern version of the Rocking Bar bridge is found on many contemporary Gretsch guitars—especially various Chet Atkins Country Gentleman®, 6120 Hollow Body, 6121 Solid Body and Tennessee Rose™ models.
For information on the remaining bridge types, Space Control™ Bridge and Adjusto-Matic™ Bridge, visit the Gretsch Guitars website.