For instance, in the setup below, only Sound Module B will sound when you play the keyboard, because it is receiving on the same channel that the keyboard is transmitting (channel 1). MIDI OUT MIDI IN MIDI THRU There is, however, one major difference: a TV lets you see only one program at a time, whereas on the Dr. Synth you can receive and play data on up to 16 MIDI channels at once! This way you can take 16 Parts, one per channel, and play them all at once, with a different instrument for each channel. In general, any sound module that can do this is called “multi-timbral”. The Dr. Synth is a multi-timbral sound module when it’s in Multi mode. •Omni Mode When Omni Mode is on, the Dr. Synth will respond to all MIDI messages—no matter which channel they were received on. 2. MIDI Messages Handled by the Dr. Synth There are a variety of MIDI messages and each has information about a particular kind of performance nuance. MIDI messages are broadly divided into Channel Messages (those that have information specific to a channel), and System Messages (information that applies to the system as a whole). •Channel Messages The MIDI messages that transmit the actual performance data are Channel messages, and these are the ones that do most of the actual work of controlling the MIDI instrument. As there are many different kinds of MIDI instruments, what exactly is controlled by MIDI messages depends on the design of a particular instrument. Note Messages These contain information about keyboard performances, including the following: Note number A number indicating the note (key) that was pressed or released. Note on A message indicating that a note (key) was pressed. Note off A message indicating that a note (key) was released. Velocity A number indicating how strongly the note (key) was pressed. 65 Each note on the keyboard is represented by a number between 0 and 127, with middle C (C4) being Note Number 60. On a drum set, each Note Number defines a different percussion instrument, so that you can play just that one sound by sending the appropriate Number. Pitch Bend Messages These transmit data about how the pitch bend lever on a synthesizer has been used. Program Change Messages These transmit Tone switching commands. In general you can switch among 128 different Tones (Program Numbers 1 to 128). On the Dr. Synth, you can also switch to Tone Variations using Control Change messages. Control Change Messages These transmit data about performance-enhancing features like vibrato, hold and volume. Each feature is assigned an identifying Controller number between 0 and 127. Not all MIDI instruments have the same features, so response to Control Change numbers will vary. On the Dr. Synth, the value of Controller #0 is used with Program Change messages to switch to a Tone Variation. •System Messages System Messages include SysEx (system exclusive) and messages needed for timing and synchronization. These messages affect the system as a whole and are not broken up into specific channels. The Dr. Synth can only handle SysEx messages. System Exclusive Messages SysEx messages are used for controlling special features of a particular MIDI device. In general, you can swap SysEx data with any other MIDI device made by the same manufacturer. They are also used to transmit Dr. Synth system and Part settings to an external sequencer. •MIDI Implementation Chart MIDI allows many different musical instruments and devices to exchange data. It is not necessarily the case, however, that all MIDI messages can be received by all MIDI devices. For example, you may set up your keyboard to send Aftertouch messages, but if the sound module you have connected doesn’t respond to Aftertouch, you will not hear the effect you’re looking for. The only way two devices can exchange a given MIDI message is if that function is available on both instruments. Each instrument has, in it’s owner’s manual, a MIDI Implementation chart that will help you determine at a glance which features the instruments have in common. The dimensions of these charts are standardized, so you can fold them as shown and physically match them to see if the MIDI messages of one device will be received by the other. MIDI MIDI ■ Switching Tones and Drums Sets With an External MIDI Device You can switch Tones or drum sets on the Dr. Synth from an external MIDI device, such as a keyboard or sequencer. •Switching Tones with an External MIDI Device MIDI IN CZ> (¿3 Œ3 C—> Ù13Q,' - -......7-. □SQDDGQOB □□□□□□□□Ö When you switch patches or Tones on the MIDI keyboard, the corresponding Program Change message is sent from its MIDI OUT connector. The Dr. Synth then receives that message and switches the Tone; the actual Tone you select is determined by the Program Change number transmitted in the message. So for example if you change to Patch 1 (whatever sound that might be) on the MIDI keyboard, that sends out a Program Change number 1 to the Dr. Synth...