Patent ID: 7812233

Claim:
An aiding device for a fretted stringed musical instrument having a neck with frets spaced longitudinally thereon and strings spaced laterally there across said neck for positioning said strings at different fret positions, wherein the aiding device is engaged over frets of an acoustic guitar to generate a chord with only two fingers of a player, comprising a molded housing which encloses twelve two position key pads installed on the key pad box, and seven single position key pads installed on the molded housing, and a strap harness that engages the molded housing to fret portion of a guitar, and an electronic circuit board installed inside said housing, and a plurality of electromagnetic actuators installed inside of the said housing just below the circuit board, and a metal spring installed inside of the key pad box just atop the electromagnetic actuators, and a plurality of pressing pins installed inside said housing just below the metal spring and over strings of the guitar, and, a rechargeable battery installed inside said housing, and each key in the set of twelve keys can play two kinds of chord for creating ‘major’ and ‘minor’ sonorities, and each key in the set of seven keys has a specific function to add one or two extra tones for chord ‘inversions’, ‘7’, ‘9’, ‘augmented’, and ‘diminished’ sonorities; and, a four position switch electrically coupled to a timer memory circuit installed inside said housing on said circuit board, and a seven position switch for setting a fixed transposition is electrically coupled to said logic circuit installed inside said housing attached to said circuit board; where, the device is longitudinally attachable to said neck with compressible retaining straps affixed to the molded frame itself thereby affixing the device with mechanical pressure to the elongated section of said neck; where, the feet of the electromagnetic actuator assembly board rest atop the face of said neck thereby creating a gap for said strings to vibrate openly above the fret and below a plurality of electromagnetic actuators connected to the corresponding pressing pins; where, the pressing pins extend transversely across the stringed face of said neck pressing said string against said fret according to the combination of said keys pads pressed, triggering said logic circuit to engage the appropriate electromagnetic actuator thus permitting said pressing pins to be pressed toward said strings thereby pinching said string against said fret in the various combinations programmed in the logic circuit; where, the circuit board positioned within said housing, said logic circuit enables a trigger circuit which directly and electrically coupled to the electromagnetic actuator thereto, wherein said electromagnetic actuator is engaged until the logic circuit is interrupted by the manual releasing of said key pad, which then triggers a reset command signal to said trigger circuit which then disengages said electromagnetic actuator.