MUSC1010 – WEEK 4

MIDI

MIDI (Musical Instrument Digital Interface)

• MIDI is associated with cheap and nasty sounds due to the fact that most computer soundcards have a very small and cheap synthesiser in them.

• Good quality sounds can be triggered by a MIDI controller or MIDI sequencer. The quality or realism of the sounds depends on the device that is producing them.

• MIDI allows the synchronisation of compatible devices• MIDI is a messaging protocol, capable of communicating;

– musical information such as note on/off, volume, modulation, etc…– information for lighting consoles – movement, dimming, colour, etc..– information to any other device (a robot, a train set, etc..) that is capable of

interpreting MIDI information.

Connecting MIDI devices

5 pin DIN plug 5 pin DIN IN/OUT to joystick port

Connecting MIDI devices is most commonly done with a 5 pin DIN plug. This is a one-way connection, and therefore most devices will have a MIDI IN and MIDI OUT port. USB and Firewire connectivity have enabled two-way MIDI information transfer. A THRU port duplicates the signal received at the IN port. This allows the user to link multiple devices.

• binary, using 2 –3 bytes (each byte is sequence of 8 bits)• first byte is a status byte. It determines the type of information being sent. The

data bytes (2nd and 3rd bytes) control the variables involved with that information.

 http://www.midi.org/about-midi/table1.shtml

 Table 1: MIDI 1.0 Specification Message SummaryUpdated 1995 By the MIDI Manufacturers Association

Message format

Status Data Byte(s) Description

(Channel Voice Messages [nnnn = 0-15 (MIDI Channel Number 1-16))

1000nnnn 0kkkkkkk Note Off event. 0vvvvvvv This message is sent when anote is released (ended).

(kkkkkkk) is the key (note) number. (vvvvvvv) is the velocity. 

1001nnnn 0kkkkkkk Note On event.0vvvvvvv This message is sent when a note is depressed (start).

(kkkkkkk) is the key (note) number. (vvvvvvv) is the velocity. 

1100nnnn 0ppppppp Program Change. This message sent when the patch number changes. (ppppppp) is the new program number.

• due to the (nnnn) 4 bit assignment for the channel number it is only possible to have 16 channels

• due to the (kkkkkkk) 7 bit assignment for the message value there are 128 possibilities for that value.

MIDI Controllers

MPC type PADS Gypsy MIDI controller

Yamaha wind controller

DJ MIDI control device

VIDEO: Brandon Epperson (lighting with Lemur)Trinexx (Wiimote and Reason)Nathan A (Lights Synced to music)ronnie9253 (Wiimote 6 controllers)

A MIDI Sequencer enables recording and editing of performance information. The simplest note information is usually plotted in a display often referred to as a piano roll;

General MIDI

• developed by MIDI Manufacturers Association in 1991• useful for internet• portable• most common system for mapping sounds• subsequent developments;

- DLS Downloadable sounds- GM2 incorporating Yamaha XG and Roland GS- GM Lite- SP-MIDI

GM (general MIDI) is a standard configuration for musical information transfer via MIDI. It enables compatibility of instrument selection when sharing MIDI sequences. It is very commonly used in MIDI files on the internet.

The General MIDI specification lays out requirements for GM compatible synthesisers, including;

- minimum polyphony of 24 voices- velocity response (how hard the input key is struck)- support for 16 simultaneous channels with channel 10 reserved for

percussion

STANDARD MIDI FILES (SMF)

MIDI files are small, internet-friendly sequence files that contain performance information. Standard MIDI files also contain information about tempo, volume, program (instrument) numbers, and other variables.

The type of MIDI file is specified near its beginning:

Type 1 is the most common type of SMF – multiple tracksType 0 is less common – all performance information on one track

Some of the other information present in a MIDI file

• Timing resolution – in ticks per beat• Tempo• Note-on and –off• Track names• Song name• Copyright notice• Marker positions and names• System exclusive events

MIDI files will usually have the extension .MID

• New Session– protools automatically generates sub-folder with same

name as the .PTF file– 44.1kHz and 16bits

• Create Tracks– Ctrl-Shift-N– Add 4 stereo INSTRUMENT tracks

• Name the first track “CLICK”. Names the remaining tracks according to the instrumentation you require.

• For the “CLICK” track click on the first button in its INSERT section and choose plug-in > Instrument > Click

• For the remaining tracks click on the first button in their INSERT section and choose the Mini Grand, Xpand2, Boom or Vacuum plugin instruments.

Starting with MIDI & Soft-Synths

Enable Inserts to be viewed in the Edit Page by clicking on

Be sure to use record your music along with the metronome “click” so it is possible to quantise the notes later