Ghost Acoustic MIDI System - Steel String Guitars Finally, a MIDI pickup system designed specifically for the acoustic guitar. Most acoustic MIDI systems use metal saddle pickups which destroy the natural and authentic sound of your acoustic guitar. The ghost Acoustic MIDI System retains a natural and amplified acoustic sound with unlimited MIDI possibilities. The ghost Acoustic MIDI System adds MIDI interface capability, studio quality acoustic preamp and unparalelled fast and accurate tracking for most steel string acoustic guitars. The same