• Musical Instrument Digital Interface

• A system that allows electronic instruments and computers to send instructions to each other
• (0's and 1's) represent voltages

• August 1983

What is a MIDI controller? 

Examples?

1. Sends input signals from the controller to the computer 
2. Akai pad controller, Roland foot controller, Oxygen 61 keyboard 

1. In - incoming data
2. Thru - duplicate data
3. Out - outgoing data 

• Attaching multiple MIDI controllers to one computer using the Thru port 
• Will have master controller and a slave 

What's the difference between serial and parallel protocols? 

Name an extra-musical example...

• Serial: MIDI data is sent down the cable one bit at a time as a stream of info 
• Parallel: allows the information to be sent down seperate wires so the message reaches the device at the same time - faster than serial interface
• Example: Computer chips use parallel interface

1. Once MIDI device can control another
2. Create rich musical textures by layering sounds from multiple MIDI defices 
3. Allows you to fix mistakes, change not pitches, fix timing, etc. 
4. Instant playback of prerecorded music 

• 16 channels 

How do you send a "note on" command?

How do you send a "note off" command? 

1. When you press a key, the "note on" message goes to the module
2. When you let go of a key, the "note off" message is sent to the module and it stops playing the note 

• A view where the keys of the piano are shown on screen and every note played is displayed for the time it is pressed 

What are some elements of a sound that can be affected by MIDI?

• Pitch
• Volume
• Velocity
• Timbre
• Vibrato 

• Velocity = associated with the initial strike of the key (fast=loud, slow=soft) 
• Volume - can be added at any point

• Master - sends commands 
• Slave - recieves commands