The Fretlight Guitar has gone through a few revisions since its creation in the early 90's. At the time of this article's publishing, Optek Music Systems, Inc. only produces and supports the most current 400 Series Fretlight Guitar. The good news is that all future developments from here will be backward compatible to the 400 Series, as it is now built upon the infrastructure of backward compatible USB.

Here is a brief description of each Fretlight Series:

The Fretlight 200 Series: The neck had holes drilled through the wood to place LED lights inside and were then covered with clear discs. The LED's were thus quite visible even when the lights were turned off. The 200 was powered by plugging it into a conventional wall outlet, and the lights were controlled by knobs on the body. Functionality of the light system was limited to display only 16 Scales and 16 chord types in any key, and individual notes.

The Fretlight 300 Series: (Otherwise known as the SmartLIGHT Guitar) This utilized an early technology to connect the guitar to a computer. The guitar required an external hardware interface box and connected via a serial port. The neck had holes drilled through the top similar to the 200 series.

The Fretlight 400 Series: This guitar series made a paradigm shift in two ways. First, the neck surface changed from wood to an advanced polymer that was translucent enough for the lights to shine clearly though, yet looked like seamless dark wood when the lights were turned off. (No more holes drilled through the next.) Second, the 400 went to the USB technology to allow connection to any computer without the need for any other external hardware. Computers recognize the Fretlight 400 Series guitar as a UID (User Interface Device) no different than it recognizes your mouse or keyboard. The functionality of the LED's also increased, allowing for the ability to play specific songs,  and allowing for a more complete list of chords and scales. (over 3,000 chords and over 500 scales actually.)

The 400 Series Guitar currently has 7 models, 4 electric and three acoustic: The FG-421 Standard, FG-431 Vintage, FG-441 Jazzmaster, FG-451 Pro, FG-405 Acoustic/Electric, FG-405 Acoustic/Electric Pro and the FG-401 Acoustic.

The next series of Fretlight guitar (500 Series?) is currently under development with no expected release date, but Optek Music Systems, Inc. is committed to pushing the boundaries of guitar education. The long-term future for the Fretlight Guitar sees possibilities like the ability to store songs, chords or scales in a separate box to take on the road, connecting to an Mp3 player or online broadcast for live instruction via the Internet, or even connecting to a personal concert with any number of famous artists whose every note played could be shown and recorded on your Fretlight Guitar at home (for you to spend hours perfecting later.) And that's just to name a few!