Casio CTK-491 User Guide - Page 33

MIDI What is MIDI? The letters MIDI stand for Musical Instrument Digital Interface, which is the name of a worldwide standard for digital signals and connectors that makes it possible to exchange musical data between musical instruments and computers (machines) produced by different manufacturers. MIDI compatible equipment can exchange keyboard key press, key release, tone change, and other data as messages. Though you do not need any special knowledge about MIDI to use this keyboard as a stand-alone unit, MIDI operations require a bit of specialized knowledge. This section provides you with an overview of MIDI that will help to get you going. MIDI Connections MIDI messages are send out through the MIDI OUT terminal of one machine to the MIDI IN terminal of another machine over a MIDI cable. To send a message from this keyboard to another machine, for example, you must use a MIDI cable to connect the MIDI OUT terminal of this keyboard to the MIDI IN terminal of the other machine. To send MIDI messages back to this keyboard, you need to use a MIDI cable to connect the other machine's MIDI OUT terminal to the MIDI IN terminal of this keyboard. To use a computer or other MIDI device to record and playback the MIDI data produced by this keyboard, you must connect the MIDI IN and MIDI OUT terminals of both machines in order to send and receive data. MIDI IN MIDI OUT MIDI IN MIDI OUT MIDI sequencer MIDI Channels MIDI allows you to send the data for multiple parts at the same time, with each part being sent over a separate MIDI channel. There are 16 MIDI channels, numbered 1 through 16, and MIDI channel data is always included whenever you exchange data (key press etc.). Both the sending machine and the receiving machine must be set to the same channel for the receiving unit to correctly receive and play data. If the receiving machine is set to Channel 2, for example, it receives only MIDI Channel 2 data, and all other channels are ignored. With this keyboard, messages received over MIDI Channels 1, 2, 3, 4, and 10 can be used for multi-timbre play of up to five different instrument parts. The tone and volume settings for these five channels must be controlled by messages sent from an external device. When sending operation of this keyboard to an external device, Channel 1 should be selected as the MIDI send channel. 625A-E-033A General MIDI General MIDI standardizes MIDI data for all sound source types, regardless of manufacturer. General MIDI specifies such factors as tone numbering, drum sounds, and available MIDI channels for all sound sources. This standard makes it possible for all MIDI equipment to reproduce the same nuances when playing General MIDI data, regardless of the manufacturer of the sound source. Though the sound source of this keyboard is not General MIDI compatible, you can still connect the keyboard to a computer or other MIDI equipment to playback General MIDI data that is widely available in stores, over computer networks, and from other sources. ❚ NOTE • General MIDI data made up of a large number of parts may not play correctly on this keyboard. • You will have most success playing back General MIDI data that has few parts and is made up of data on channels 1, 2, 3, 4, and 10. Messages There is a wide variety of messages defined under the MIDI standard, and this section details the particular messages that can be sent and received by this keyboard. NOTE ON/OFF This message sends data when a key is pressed (NOTE ON) or released (NOTE OFF). A NOTE ON/OFF message include a note number (to indicate note whose key is being pressed or released) and velocity (keyboard pressure as a value from 1 to 127). NOTE ON velocity is always used to determine the relative volume of the note. This keyboard does not receive NOTE OFF velocity data. Whenever you press or release a key on this keyboard, the corresponding NOTE ON or NOTE OFF message is sent by constant velocity from the MIDI OUT terminal. ❚ NOTE • The pitch of a note depends on the tone that is being used, as shown in the Note Table on page A-2. Whenever this keyboard receives a note number that is outside its range for that tone, the same tone in the nearest available octave is substituted. E-31 CTK481_E31_33.p65 Page 31 03.10.7, 2:58 PM Adobe PageMaker 6.5J/PPC