A guitar body having an inner sidewall forming an opening extending from a front to a back of the guitar body is provided. The inner sidewall includes electrical contacts electrically connected to a wiring of the guitar. A seat with magnets is formed about a periphery of the inner sidewall. A pickup cartridge includes a pickup, electrical contacts, and a flange with magnets. The opening is sized to receive the pickup cartridge so that the magnets of the seat attract to the magnets of the flange and releasably retain the pickup cartridge within. The electrical contacts of the pickup cartridge electrically connect with the electrical contacts of the inner sidewall.