Electronic apparatus to assist teaching the playing of a musical instrument

A music teaching device for use with a separate keyboard, comprising:

• a processor module having a standard Musical Instrument Device Interface (MIDI) input port, a processor having input lines coupled to said MIDI input port, and an output port having a plurality of output lines coupled to output pins of said processor;
• at least a first display module having an input port with a plurality of input lines corresponding to said output lines of said processor module, a plurality of lights, each of said lights being spaced to correspond to the keys of a keyboard, decoding logic having inputs coupled to said input lines and output lines coupled to said lights for activating said lights in accordance with coded signals received from said processor module;
• said processor being programmed to ignore certain MIDI signals received at said input port and, in response to note on and note off signals received at said MIDI input port, generating output signals on said output lines including said coded signals indicating which of said lights is to be controlled and indicating whether said light is to be turned on or off;
• means, coupled to said processor, for indicating which one of sixteen MIDI channels said processor will respond to;
• said processor being programmed to provide, in response to a MIDI status word with 1001 followed by a four bit number corresponding to said one MIDI channel, a light on signal on one of said output lines and a coded signal to select one of said lights corresponding to a note number data byte following said status word, shifted by a shift amount stored in said processor to place middle C at a desired one of said lights;
• said processor being programmed to provide, in response to a MIDI status word with binary 1000 followed by a four bit number corresponding to said one MIDI channel, a light off signal on one of said output lines and a coded signal to select one of said lights corresponding to a note number data byte following said status word, shifted by a shift amount stored in said processor to place middle C at a desired one of said lights;
• and
• said processor being programmed to provide said coded signals in response to additional note number data bytes without additional status bytes, with an on signal being provided unless a velocity data byte following said note number data byte is zero, with an off signal being provided in response to such zero velocity data byte.

A music teaching device for use with a separate keyboard, comprising:

• a processor module having a standard Musical Instrument Device Interface (MIDI) input port, a processor having input lines coupled to said MIDI input port, and an output port having a plurality of output lines coupled to output pins of said processor;
• a first display module having an input port with a plurality of input lines corresponding to said output lines of said processor module, a plurality of lights, each of said lights being spaced to correspond to the keys of a keyboard, decoding logic having inputs coupled to said input lines and output lines coupled to said lights for activating said lights in accordance with coded signals received from said processor module, and an output port coupled to said input port;
• said processor being programmed to ignore certain MIDI signals received at said input port and, in response to note on and note off signals received at said MIDI input port, generating output signals on said output lines including said coded signals indicating which of said lights is to be controlled and indicating whether said light is to be turned on or off;
• at least a second display module, identical to said first display module, having an input port removably connected to said output port of said first module such that a spacing between a last light of said first module and a first light of said second module equals a spacing between two keys on said separate keyboard;
• each of said first and second display modules including a plurality of select lines coupled between said input and said output ports, the position of said select lines being shifted between said input and output ports;
• each of said first and second display modules including a plurality of return lines coupled between said input and output ports, one of said return lines being coupled to a voltage to indicate to said processor the presence of said board, the position of said return lines being shifted between said input and output ports;
• said processor being programmed to place middle C at the leftmost light when a single display module is connected, and otherwise to place middle C near the middle of the display modules.