Introduced in the late 80's by Ibanez and Steve Vai, this electric guitar has an additional bass string, tuned one fourth below the standard tuning. The novelty of an extra string soon wore off though, and the Ibanez line of guitars was considered a flop.

The potential of these guitars was however recognized by a few musicians, in particular Swedish metal band Meshuggah, who have used the Ibanez Universe guitars exclusively since the early nineties. The seven string guitar, and the Ibanez line especially, have since been made more popular by American 90's metal acts Korn, Deftones and Fear Factory. So much in fact, that Ibanez reissued their line of 7 string guitars in the late 90's. A few other brands, like ESP, BC Rich and Schecter, also began making 7 string guitars as regular models (as opposed to custom models).