Although the synthesizer first became widely known with the release of Wendy Carlos' Switched-On Bach in 1968, the first electronic synthesizers were designed and built more than 50 years earlier with devices such as Leon Theremin's eponymous gesture-controlled instrument and Lee De Forest's Audion piano (De Forest also invented the modern amplifying vacuum tube). Before Carlos, though, most synthesizers had been used in the world of avant-garde and experimental musicians. Carlos' use of Robert Moog's modular synth put synthesis in the forefront of popular music making, where it's remained ever since.
It was with the development of new systems that stepped beyond the strictly patchbay-based sound editing and frequently unstable oscillators of early attempts to new, far-easier-to-program interfaces and storable presets that synths became something all keyboard players began to add to their arsenals. When creative players began to realize that synths could do much more than just imitate other instruments, but make entirely new sounds that could not otherwise exist, the use of synths expanded further and further. Today's digital keyboards almost all use some form of synthesis to create their sounds, whether sample-based, additive, subtractive, AM, FM, granular, phase-distortion, physical modeling or some combination of these different approaches.
As you may suspect, there are a lot of ways to synthesize sound, and each has individual strengths and weaknesses. While we don't have the space to go into them here, a deeper understanding will do you good, and Guitar Center offers a number of books with great resources for gaining knowledge about synthesis.
From small, monophonic analog synths to massively powerful digital workstations with built-in sequencing and recording capability, the contemporary range of synthesizers can be truly mind-boggling. Spend some time discussing your needs with our keyboard department, and we'll help you zero in on the one that's right for you.