variedsound

Does anyone here know of a schematic for a circuit that wires LEDs to your pickups and the brightness of the LEDs vary directly with input of pitch coming into the pickup(For Example: Playing higher notes makes LEDs really bright and lower notes make them dull)? Has anyone ever done something like that? I know it can be done, I just want to know if I need to draw my own schematic for it. helphelp plx.