This invention relates to a musical instrument, specifically a frame cajon comprising a cuboid frame with structural surfaces on the top and bottom that completely support the weight of the player allowing multiple playable sides to be attached for the percussionist. The method further includes, for each of the plurality of speech applications, replacing each of the grammar tags in the first output set with a class identifier of an application-generic class, to produce a second output set. To perform optical performance monitoring on the output ports, a monitoring component of each output signal is extracted, and these monitoring components are then combined. Trench MOS based TVS device provides an enhanced gain operation, while device provides a top side drain contact. When the solenoid is mounted, the elastomeric retaining device biases the lamination stack against the mounting surface.