A soundhole accessible musical instrument control platform mounted inside the body of a musical instrument requires no physical alterations to the instrument, allowing the user convenient and ergonomic access to the control platform through the soundhole while using the musical instrument. The control platform includes a circuit platform, mounted inside the instrument with adhesives, separably attached to a mounting bracket. Control detents and markings are easy to feel and to read and thus provide feedback for control position and the relative degree of effect. The controls are surrounded by a cosmetic bezel that hides the actual mounting mechanism and circuitry. Any combination of controls, circuitry, and sensors may be used. Power is either provided onboard or offboard. An output connector may be integrated into the circuit platform or via an endpin jack. Input signal connectors, present on the circuit platform, are configured to accept pickups that are mounted either internally or externally to the body of the musical instrument, or to accept a combination of internal and external pickup mounts.