Since it is possible to have many MIDI levels, Classic Console Control Computer provides a unique feature to make accessing the MIDI-levels convenient. This feature is called direct-access pistons. These pistons can be used in either of two ways. To illustrate how these work, suppose an organ is configured with 5 direct-access pistons. These pistons then could be configured either:

• To step through MIDI-levels 1 to 5 or,
• To jump directly to any MIDI level.

This approach is extremely useful in that it allows an organ to have many more MIDI levels than pistons. The MIDI level to which a direct-access piston jumps is settable by the organist.

There are other ways to configure an organ with MIDI-stops. Some builders do provide a MIDI division, with couplers such as MIDI-to-Swell, MIDI-to-Great, etc. With the Classic system, a combination of the MIDI division approach and the fully integrated system is possible and would be preferred because the integrated approach allows the organist to more fully exploit the resources of the expander.

In situations where the MIDI-stops can be controlled on the external MIDI device, a console could be configured simply with couplers such as MIDI-to-Swell, MIDI-to-Great, etc. When the coupler to a manual is turned on, the organ would send out MIDI data for the manual to the MIDI device. While this is a fairly low-cost approach to implementing MIDI on a pipe-organ, the disadvantage is that the organist cannot select specific MIDI-stops with the pistons on the organ console.

We do not recommend one scheme which allows the organist to select MIDI-stops via regular general and divisional pistons. With this method, MIDI-stops do not have drawknobs or tabs. Instead, some means is provided to allow the organist to assign MIDI-stops to the pistons and then the stops are turned on and off only by pressing the pistons. The danger here is that the traditional distinction between organ-stop controls and combination pistons has been violated, and confusion could result! This method also makes simultaneous selection of multiple MIDI-stops both impractical and confusing while manually turning individual stops on or off is impossible. If a piston-controlled approach was the only option, then the preferred approach would be to provide a set of lighted pistons dedicated to exclusively controlling MIDI-stops. A Classic Console Control Computer would then allow these pistons to be integrated into normal combination action operation.