MIDI

Musical Instrument Digital Interface

What is MIDI?

MIDI is an acronym for Musical Instrument Digital Interface.

The term is used for both hardware and software.

What is MIDI?

• MIDI protocol provides a standardized and efficient means of conveying musical performance information as electronic data.

• MIDI information is transmitted in "MIDI messages", that tell a synthesizer (or sound card) how to play a piece of music.

What is MIDI?

The MIDI specification allows for a maximum of 16 channels of information to be sent from one MIDI device to another using a standard MIDI cable.

This allows a MIDI sequencer to play back up to 16 different channels of MIDI information that are entirely independent of each other.

How do MIDI channels work?

Assume a MIDI sequencer playing a multi-timbral sound module where channel 1 is playing a flute sound, channel 2 is playing a clarinet sound, and channel 3 is playing a harp sound. When the sequencer sends a pitch bend message on channel 3 to the harp, only the harp receives the message; the other 2 channels completely ignore it.

What is a multi-timbral device?

A Multi-timbral keyboard or sound module has the capability to receive MIDI information on more than one channel simultaneously. All General MIDI keyboards and sound modules, by definition, are multi-timbral.

(We’ll discussion General MIDI later in this presentation.)

A Brief History of MIDI

It is important to remember that MIDI was created to simplify live performances. During the 1981 fall convention of the Audio Engineering Society, Dave Smith and Chet Wood, two engineers from synthesizer manufacturer Sequential Circuits (creators of the popular Prophet-5 keyboard) proposed an industry standard for an electronic musical instrument interface. The idea was that performers should not have to create custom cables and devices to connect synthesizers. Instead, they should be able to "plug and play" with units from different manufacturers.

A Brief History of MIDI

Dubbed the Universal Synthesizer Interface (USI), this draft proposal was modified by the engineers of synthesizer manufacturers Oberheim, Roland, Korg, Yamaha, and others of their ilk. A consensus was orchestrated on the revised proposal and in late 1982 (drum-rolls please) the first set of universal MIDI specifications was adopted.

A Brief History of MIDI A detailed history of MIDI is available on the

class web site:

(Tutorials Page)

MIDI is Everywhere

Most film and TV scores, as well as popular recorded music is written and performed using electronic keyboards and other MIDI-equipped musical instruments. (Thanks to advances in digital sampling and synthesis technologies, the orchestra playing behind that big-screen block buster is more likely to be the product of MIDI than a real orchestra with dozens of acoustic instruments.)

MIDI is Everywhere

MIDI is also easy to find in the world of personal computing. If your computer has a sound card, it most likely also has the ability to play MIDI files (using a built-in hardware or software synthesizer that responds to MIDI messages), and with an adapter can also be connected directly to other MIDI-equipped products, allowing you to take advantage of various computer programs that can help you learn, play, create and enjoy music.

MIDI is Everywhere

MIDI also has some other interesting and popular uses. For example, MIDI Show Control is a command and control language used with rides at major theme parks and events at Las Vegas casinos, and MIDI Machine Control is used in recording studios to synchronize and remotely control recording equipment.

MIDI is Everywhere

MIDI is being used to generate ring tones in mobile phones. MIDI ring tones sound far better because they are polyphonic (play more than one note at one time) and because they use music synthesizers that produce a wider variety of sounds than previously possible.

MIDI is Everywhere

There are over 300 companies around the world making products that support MIDI -- well known companies such as Apple and Microsoft, Roland and Yamaha, Nokia and Sony/Ericsson, among others.

MIDI is Everywhere

Can you name other possible uses for, or applications of, MIDI technology?

The Benefits of MIDI

MIDI is a technology that represents music in digital form. Unlike other digital music technologies such as MP3 and CDs, MIDI messages contain individual instructions for playing each individual note of each individual instrument. So with MIDI it is actually possible to change just one note in a song, or to orchestrate an entire song with entirely different instruments.  

The Benefits of MIDI

Since each instrument in a MIDI performance is separate from the rest, it’s easy to "solo" (listen to just one) individual instruments and study them for educational purposes, or to mute individual instruments in a song so that you can play that part yourself.

The Benefits of MIDI

Play with a band: Standard MIDI Files are available for many

popular songs, and when used with a personal computer or digital piano make it possible to have an entire backing band play along with you at whatever speed (tempo) and in any pitch (key) you desire. MIDI files are perfect for practice, as well as for performing when additional musicians are not available.

The Benefits of MIDI

Record and edit your performance A MIDI Sequencer can record your performances for

listening at a later time, and even save your performance in Standard MIDI File format for playback on other MIDI systems. A MIDI Sequencer is a way to evaluate your own progress or to study how someone else plays.

Since all MIDI data is editable, you can edit any imperfections. If you play a wrong note, you can just change it using the Sequencer's editing tools. If you find you just can't play fast enough to keep up with the tempo, you can slow it down for recording and speed it back up for playback. 

The Benefits of MIDI Compose Music Arrange and Orchestrate Educational Uses Auto-Accompaniment Recording Studio Equipment Song Files

Standard MIDI Files ("SMF" or *.mid files) are a popular source of music on the web, and for musicians performing in clubs who need a little extra accompaniment.

Stage Lighting Controllers Many performing bands use MIDI to synchronize lighting

cues with their music.

The Benefits of MIDI

Play any instrument Most digital pianos and other MIDI instruments

come with hundreds of different sounds (pianos, trumpets, violins, guitars, basses, etc.) that you can play yourself or play via a MIDI sequencer to create orchestrated music. 

General MIDI

Most MIDI keyboards today include the General MIDI sound set, sometimes by themselves, but often with other sets of sounds. By having at least one standard set of sounds, files could now be exchanged and successfully played back on all GM compatible instruments.

In most cases, the GM sound set is based on actual wave samples recorded from the original instruments. The difference in cost for a wave based sound card versus a synthesizer only sound card is minimal, and easily worth the difference.

General MIDI

The General MIDI specification includes which instruments should be played, how many MIDI channels the device must handle, and how many voices can be played back at the same time.

MIDI Channels: A General MIDI device must be able to simultaneously play

back a different instrument or patch on each of its 16 channels. Drums and percussion instruments are always assigned to MIDI channel 10.

General MIDI

Instruments or Sounds: The General MIDI sound set must include at least 128

preset instruments in the exact order as specified in the GM Instrument Patch Map. There is also a specific GM Percussion Key Map based around 47 percussion sounds.

Voices or Polyphony: A General MIDI device must be able to play back at least

24 voices simultaneously divided between melodic and percussion instruments. These voices must be able to be dynamically allocated or assigned as needed. All voices must respond to velocity.

General MIDI

Channel Messages: General MIDI devices must also support

continuous controller messages including: Channel Volume Modulation Wheel Velocity Panning Sustain Pitch bend Channel Pressure & Expression.

General MIDI

There are 128 instruments arranged into 16 families.

Note that the instrument numbers shown on the next slide range from 1-128, though the actual value used in the MIDI Program Change messages will be 0-127.

General MIDI

PC # Instrument Family PC # Instrument Family

1-8 Piano 65-72 Reed

9-16 Chromatic Percussion 73-80 Pipe

17-24 Organ 81-88 Synth Lead

25-32 Guitar 89-96 Synth Pad

33-40 Bass 97-104 Synth Effects

41-48 Strings 105-112 Ethnic

49-56 Ensemble 113-120 Percussive

57-64 Brass 121-128 Sound Effects

General MIDI A complete listing of all 128 general MIDI sounds is

locate on pages 8-10 of your MIDI tutorial (located on the class web site).

General MIDI General MIDI drum sounds are found on

Channel 10.  General MIDI defines 47 drum sounds, with each

being allocated to a separate MIDI key. The number before each drum sound corresponds to the keys on a 61-note MIDI keyboard

General MIDI (Channel 10)Key # Note Drum Sound Key # Note Drum Sound

35 B1 Acoustic Bass Drum 59 B3 Ride Cymbal 2 36 C2 Bass Drum 1 60 C4 Hi Bongo 37 C#2 Side Stick 61 C#4 Low Bongo 38 D2 Acoustic Snare 62 D4 Mute Hi Conga 39 D#2 Hand Clap 63 D#4 Open Hi Conga 40 E2 Electric Snare 64 E4 Low Conga 41 F2 Low Floor Tom 65 F4 High Timbale

42 F#2 Closed Hi-Hat 66 F#4 Low Timbale 43 G2 High Floor Tom 67 G4 High Agogo 44 G#2 Pedal Hi-Hat 68 G#4 Low Agogo 45 A2 Low Tom 69 A4 Cabasa 46 A#2 Open Hi-Hat 70 A#4 Maracas 47 B2 Low-Mid Tom 71 B4 Short Whistle 48 C3 Hi-Mid Tom 72 C5 Long Whistle 49 C#3 Crash Cymbal 1 73 C#5 Short Guiro 50 D3 High Tom 74 D5 Long Guiro 51 D#3 Ride Cymbal 1 75 D#5 Claves 52 E3 Chinese Cymbal 76 E5 High Wood Block 53 F3 Ride Bell 77 F5 Low Wood Block 54 F#3 Tambourine 78 F#5 Mute Cuica 55 G3 Splash Cymbal 79 G5 Open Cuica 56 G#3 Cowbell 80 G#5 Mute Triangle 57 A3 Crash Cymbal 2 81 A5 Open Triangle 58 A#3 Vibra-slap

General MIDI Where do I find these “General MIDI” sounds when using

Finale?

General MIDI Where do I find these “General MIDI” sounds when using

Sibelius?

General MIDI Even though the General MIDI specification lists which

sounds are to be used, it does not define the way the sounds will be reproduced. This being the case, not all General MIDI synthesizers are created equal.

MIDI keyboards and sound modules can significantly differ in sound quality. The same holds true for GM based PC sound cards. Some can produce amazing reproductions of the original instruments, while others do not succeed nearly as well.

General MIDI

Generally, you get what you pay for in terms of sound quality, although like all technology-based products, the investment needed to acquire great sounding instruments seems to get lower every week!

Benefits of General MIDI Your Link To Compatibility With The Rest Of The World

Predictable behavior! This alone makes GM extremely worthwhile in what can

otherwise be a rather unpredictable environment. With a GM compatible instrument, you have an organized industry standard set of sounds from which to choose. It will be compatible with any commercial MIDI song files you may purchase, and your instrument will be compatible with those of your peers. Most software programs default to the GM sound list at start up, negating the need to create a custom sound list.

Benefits of General MIDI The benefits of GM extend well beyond the individual user.

Now, if you compose music using the GM instrument set, you can be confident that your MIDI songs can be enjoyed by anyone else who owns a General MIDI compatible instrument. Prior to GM, a MIDI song file would often prove useless to the recipient because of the wide variance of instrument assignments between different makes and models of MIDI instruments.

The cooperative effort among manufacturers whose instruments support the General MIDI standard has catapulted the usefulness of MIDI into the mainstream of musical creativity.

Beyond General MIDI

In anticipation of greater demands from consumers, Roland and Yamaha developed "extensions" of General MIDI in their respective GS (general standard) and XG (extended general) MIDI instruments. These instruments are compatible with the GM standard, yet offer a variety of additional features, such as reverb/chorus effects and more instrument sounds over and above the basic GM specification.

How to tell if an instrument is General MIDI compatible Look for one (or more) of the following logos, either

stamped or painted on the instrument itself, or on the owner's manual that came with the instrument.

The instrument is General MIDI compatible if one or more of these logos are present.

General MIDI: Summation With general MIDI, one has a simplified, convenient means

of composing, recording, and playback of music using software and a computer. The primary advantages of a general MIDI instrument are:

a consistent industry standard set of sounds from which to choose.

compatibility with any commercial MIDI song files . assurance of compatibility with others who own a GM

instrument. most software programs (including Finale & Sibelius) will

default to the general MIDI sound list at start-up. spending more time making music instead of serving as a

"MIDI Technician" for non-General MIDI instruments!

Creating a MIDI file using Finale®

Simply input the notation of your music the same way you have for your exercises and projects. When ready to create

your MIDI file, choose SAVE AS from the File Menu.

Creating a MIDI file using Finale®

Make sure that your file name contains NO SPACES or special characters, and is no more than 22 characters in length (otherwise, it will not work within your web site). Under FORMAT, choose Standard MIDI. In the subsequent dialog box, choose Format 1, and click OK.

Creating a MIDI file using Sibelius®

Again, make sure that your file name contains NO SPACES or special characters, and is no more than 22 characters in length. Under FILE>EXPORT, simply choose MIDI. Click SAVE.

That’s it!

Any Questions?

Now’s the perfect time to ask any questions you may have regarding:

MIDI Next class period, we’ll discuss digital editing and the

conversion of WAV files and/or AIFF files into mp3 files.