The Korg GEC3EXP - Group Electronic Music Education Controller is a digital audio routing device that plays a central role in Korg's Group Music Learning System. The system allows educators to teach up to 64 students distributed across 32 stations about electronic music technologies such as MIDI keyboards, guitars, sound modules, computer soundcards, and more.

It is suitable for Piano Labs, Guitar Labs, Technology Labs, Drum and Percussion Labs, Synthesis Labs, Computer Labs, and other educational workshops. The controller connects to up to 32 of Korg's SCI3V3 student audio interfaces via RJ45 Ethernet cable and works with Korg's propriety SB40GEC headphones with built-in gooseneck microphone that allow teachers and students to hear audio over the network and communicate with one another.

For flexibility, the controller can operate in one of three different modes. In Lecture Mode, the device allows an educator to present information to students through a microphone while also allowing students to hear their instruments and devices connected to their interfaces.

In Practice Mode, each student is able to work independently and only hear his or her own instrument. The teacher has the ability to listen to what each student is doing as well as initiate two-way communication with the student.

In Group Mode, students can be placed in groups of two or more so that each may hear his or her own instrument as well as the instruments of the other members in the group.

The device features a touch-screen user interface that allows for custom setups, and displays the names of each student at each station. Teacher data, class information, and MIDI settings can be stored and recalled for future classes. The system also features a version of MIDI that allows the teacher to remotely control a student's MIDI keyboard connected to the student's interface. MIDI keyboards can also be split so that two students may independently work from the same keyboard. An S/PDIF output on the GEC3EXP allows for any workstation within the system to be recorded for future playback.

For I/O the unit includes left and right RCA connectors for instrument inputs, two left and right RCA aux stereo input pairs, a left and right stereo RCA tape output, a left and right stereo RCA room output, MIDI in, MIDI Out, a S/PDIF coaxial connector, and a port for interfacing with the student interfaces on RJ45 Ethernet connection.