Gibson Guitar Corp. will start shipping an initial run of its new digital guitar in April. The first run of 3,000 instruments will retail for about $2,600 each. It looks, sounds and acts like a Les Paul, but it's not. The technology in the standard electric guitar dates to the 1920s, with few major changes. The electric guitar is monophonic: The sound from each of the six guitar strings is "picked up" and sent as an analog signal to devices such as amplifiers and receivers.