MIDI

Give us a little more information here. Where is it used with Cakewalk? How did you find out you need it? etc. And if you don't know what it is, how do you know you need it? Is it possible that you mean MIDI rather than MDI?




    

Edited by Trademark - January 22 2007 at 17:14

er :D you can connect the midi out on your keyboard or drum pads (although personally I imagine you playing a keytar) to the midi in port on the back of your soundcard, and then cakewalk should be able to register your input. maybe the settings won't work at default but there'll be sites that tell you how to configure these things.

midi's an interface, it helps to standardize... things. your question is vague so I respond likewise :D

MIDI stands for Musical Instrument Digital Interface. it is a machine language that allows your keyboards to "talk" to Cakewalk.

Here some info from a handout I give my students in a computer music class I teach. I hope it helps.

Some History:
MIDI is an acronym for Musical Instrument Digital Interface. Essentially it is a digital language, optimized
to control electronic musical instruments, with standardized hardware connections and transmission speeds
designed to allow devices by different manufacturers to communicate effectively with each other. MIDI was
the brainchild of Roland’s Ikutaro Kakehashi. He initially collaborated with Sequential Circuits’s Dave
Smith and Oberheim Electronics’s Tom Oberheim in the early 1980s. Very soon a number of other Japanese
companies — notably Yamaha and Korg — had joined the effort. Every aspect of the development of MIDI
from the specs to its name was the result of much back and forth discussion and compromise. Differences
were generally resolved in favor of keeping MIDI simpler in its design, more efficient in its use of hardware
resources, and cheaper to produce. This was in keeping with Kakehashi’s vision of MIDI as serving the
consumer market — and in contrast to one of the more noticeable industry trends of that time toward ever
bigger, more integrated and powerful, and more expensive products for well-financed industry professionals
(e.g., Fairlight, Synclavier, GDS) At the January 1983 NAMM show, two off-the-shelf units — a Roland JP-6
and a Prophet 600 — successfully communicated with each other when simply connected together by MIDI
cables. Later that year Yamaha released the DX7, which became the first big hit of the MIDI era, selling
over 200,000 units. The MIDI revolution, aided significantly by the concurrent explosion in the personal
computer industry, was in full swing. Indeed the real power and flexibility of MIDI is best realized in a
system that connects several MIDI devices to a personal computer. In the ensuing years, adventurous
programmers, engineers, and musicians have extended MIDI applications far beyond their original intent,
but the basic protocols and limitations are still intact. By the end of the 1980s, the industry had designed a
subset of MIDI features called General MIDI for the purpose of further standardization of several aspects of
synthesizer design. General MIDI increases compatibility between synthesizers in several ways: by
ensuring certain minimum standards (128 different preset sounds in ROM; 16 different simultaneous preset
sounds, or “patches”; at least 28 simultaneous or overlapping notes); by imposing limits on timbral diversity
(preset patch #1 will always be a piano; preset patch #127 will always be a gunshot, etc.); and by
standardizing most non-pitched percussion (drums and percussion will always occupy track 10; each
instrument is assigned as specific note on the keyboard — e.g., the bass drum will always be triggered by
note #36, the lowest C on a standard 60-note keyboard).
Some MIDI Basics:
MIDI can be used to send and receive a variety of messages between MIDI devices. Note-on and note-off
messages are perhaps the most basic, but there are many more. Key velocity (how fast or hard the key was
struck); pitch bend; key and channel pressure (how much downward force is maintained on the key after the
initial attack); patch change messages (which call up different stored presets from RAM or ROM); data from
modulation wheels, sliders, foot pedals and switches; are all typical types of events handled by MIDI. An
important distinction to be understood is that MIDI does NOT generally deal directly with audio. (Years
after its introduction, when MIDI samplers began to be popular, a method of sending and receiving samples
over a MIDI network was developed — the MIDI Sample Dump Standard— but it is nowhere near fast
enough to actually listen to the results as audio.) In order to actually hear the results of MIDI transmission,
you need to send the MIDI data to a synthesizer, which then creates sounds based on the incoming MIDI
messages.
Some Technical Stuff:
MIDI employs a serial interface for communication — meaning events are handled one at a time
sequentially (imagine a single train traveling in one direction on a track). This was, in fact, one of the
biggest compromises in establishing a consumer oriented standard. Parallel communication (imagine a
large multi-lane freeway with cars whizzing in many lanes and both directions) was favored by some of the
developers because of its potential for handling far more events and data in a given time, but the cost
difference would have been significant. Parallel communication would also seem the logical choice if one
thinks about all the events in music that seem to happen simultaneously to our ears. However, by using a
serial transmission with a high enough speed (31.25 Kbaud or 31,250 bits per second) it is possible to send
over 3,000 MIDI events per second. This is more than enough speed to fool most ears into accepting the
illusion of simultaneity and to avoid timing glitches for most casual users. More advanced and demanding
users may notice problems, however, if they begin to approach that maximum density of data, or if they
require a large number of events to be executed simultaneously.
MIDI devices are equipped with both a transmitter and a receiver that make use of a computer industry-
standard connector— the 5-DIN pin —though only two of the pins are actually used by MIDI. Again the

adoption of this connecting system with 3 “wasted” connectors was controversial, but at least the use of a
computer industry standard connector instead of a simple stereo connector helped to strengthen the
distinction between the data flowing through a MIDI system and the analog audio and control signals to
which electronic musicians where accustomed. It also virtually eliminated the possibility of delicate
computer components being subjected to these other signals. Connecting the MIDI OUT jack of one unit to
the MIDI IN jack of a second unit allows the first to send MIDI messages to the second. Assuming both
units are keyboard synthesizers, you could now access and play the sounds of the second keyboard using the
keys buttons, wheels, and knobs of the first. If you also connect the second keyboard’s MIDI OUT to the first
keyboard’s MIDI IN, you could then control either keyboard from the other. To connect a third synthesizer
to the system, you could connect the MIDI THRU jack of either the first or second keyboards to the MIDI IN
of the third synthesizer. This new addition to the set-up would then be controllable by whichever keyboard
did not have the MIDI THRU jack in use. In other words, the MIDI THRU jack sends out data received by
its own MIDI IN jack, not messages generated from within itself.
To connect these standard MIDI devices to a computer generally requires a computer-specific MIDI interface
— with the standard MIDI IN and MIDI OUT jacks (at least one of each) — which is connected to one of the
computer’s serial ports. This could be accomplished with an internal card or with a stand-alone unit.
Depending on your choice of MIDI devices, you may be able to skip the dedicated unit since many keyboard
synthesizers and tone generators now have built-in switchable interfaces for PC and Macintosh computers.
However, as a MIDI system becomes larger and more complex, the increased convenience, flexibility, power,
and features of a stand-alone unit become more valuable.
Some Really Technical Stuff
MIDI is an 8-bit binary language with two main types of bytes: status bytes and data bytes. The status byte
uses the first 4 bits to announce what type of data byte(s) will follow and uses the second 4 bits to indicate
which MIDI channel is affected by those data byte(s) it precedes. With four bits it is possible to count from 0
to 15 — so this limits MIDI to a maximum of 16 different channels for the data bytes to use on any single
MIDI cable. Other bytes of MIDI data make use of the first bit to indicate whether what follows is a status
byte or a data byte (1=status byte; 0=data byte).   This leaves 7 bits for the actual message, so the range of
expressible numbers runs from 0-127 (or 128 different values). This limitation affects a broad range of MIDI
messages. Possible notes numbers run from 0-127, with middle-C being note #60. Key velocities (both down
and up), Modulation wheels, keyboard sliders, foot controllers, patch change messages (which change the
synthesizer from one preset to another), channel pressure (how hard you continue pressing down on the key
after it is sounded), etc. all have a maximum range of 0-127. Even the number of possible MIDI controllers
total 128. Many of the more common controllers have assigned numbers (Modulation = 1; MIDI Volume = 7;
Pan = 10, Sustain Pedal = 64, etc.), while others are left undefined for future expansion. Pitch wheel
messages often use two data bytes in order to enhance the resolution of continuous pitch changes and
smooth out potential bumps. MIDI also uses System Messages which address devices irrespective of MIDI
channel. System Common Messages are primarily used for timing messages of the sort required by devices
with built-in sequences (more on sequencers later). Another powerful type of message, System Exclusive
Messages (or SysEx Messages) allow for communication with a specific instrument in the system and are
used for extending the real-time programmability of a device. It is this type of MIDI message that is at the
heart of all external or computer based synthesizer editor/librarian packages.
This binary number crunching goes on in the background and is largely unobserved by the average MIDI
user. Certainly it is not essential to become fluent in 8-bit binary conversions in order to use make good use
of MIDI. Most synthesizer interfaces and certainly all modern computer-based sequencing software bury
most of this number crunching behind layers of sophisticated, user-friendly graphics. But every once in a
while, when trouble-shooting or looking for new ideas, it can be helpful to understand a little about what’s
really going on in the background. For example, it is useful to understand that sending a MIDI note-on
message for note #60 does not ensure that you will get an in-tune middle-C. The receiving synthesizer may
be set up to transpose it up or down anywhere from a few cents to an octave or more. This is in fact one way
to exceed the 128-note range of MIDI. Also a given pitch bend message will have a different result when
sent to a synthesizer set up with a pitch bend range of +/- 2 half-steps versus one set up with a range of +/- 1
octave.
Some Common Uses For MIDI:
Aside from simply connecting one MIDI synthesizer to another and playing two at once, one of the main
things MIDI is used for is sequencing. This can be accomplished with a built-in or on-board sequencer in a
keyboard or drum machine, or a dedicated stand-alone device, or a computer-based software sequencer. The
built-in devices offer the convenience of easy portability (and perhaps to a certain extent stability).
Computer-based sequencers offer a host of user-friendly editing features, virtually unlimited storage, ability
to print sheet music, etc., and at the high end the ability to combine MIDI with digital audio recording,
Computer Skills for Musicians -4-
which greatly expands the realm of possibilities. All MIDI sequencers accomplish essentially the same two
tasks. They record and store MIDI data such as note-on, note-off, pitch wheel changes, modulation wheel
changes, etc. — either in realtime or otherwise. They also handle playback of these stored events in
realtime. The non-realtime aspect of MIDI recording is a powerful difference between recording MIDI and
recording audio. The duration and timing of note messages can be preset and then notes may be entered at
any speed irrespective of the final desired result. An hour’s worth of long, slow drones could be entered in
seconds or minutes; a half-second flurry of notes could be entered with a coffee break taken in the middle.
Inaccuracies can easily be edited or fixed without the necessity of rerecording a passage. Playback can be
sped up or slowed down without affecting the pitch. Transpositions (large-scale or small-scale) can be
executed quickly without a change in playback speed. (While modern digital audio workstations may be able
to perform these editing tasks that require the ability to handle pitch and speed independently, the process
is much slower, more limited in scope, and often results in degraded audio quality.)
In addition to sequencing, some other notable uses for MIDI include the editing and storage of libraries and
banks of sounds for synthesizers. Excluding some very low-end models, most synthesizers have some
programmable memory for users to create and store their own sounds. Computer-based editor/librarian
programs utilize MIDI’s System Exclusive features to allow unlimited storage and easier editing of these
sounds.
A third common use of MIDI technology is as an aid in preparing printed music. As mentioned before, some
computer-based sequencing programs have music printing ability. Likewise many software applications
primarily dedicated to music printing use MIDI to speed up the process of getting note information into the
computer and for “proofing” the music for wrong notes.
In all of these previous uses, MIDI data is created by the user one event or parameter change at a time and
stored for future use. There is another class of MIDI application which involves the use of a computer
program to generate MIDI events in realtime according to certain formulas or algorithms. In some cases the
user gives the program some input to start the process and then the formula takes over, outputting
additional MIDI data. A simple example of this would include a MIDI-based arpeggiator such as can be
found in some synthesizers and software sequencers. Holding down a collection of notes generates a series of
patterned repetitions and/or transpositions of the held notes. A computer program such as Band-In-A-Box
generates MIDI data based on chord and style information entered into the program by the user. Select a
different style from the menu and a new algorithm outputs a completely different drum pattern, different
bass line, different keyboard chord voicings, and so on. At least one application, Opcode’s MAX, is designed
specifically to enable users to design their own algorithms to generate MIDI data. Users can create their
own mathematics formulas, convert one type of MIDI data into another (key velocity into pitch bend,
modulation wheel into note number, etc.), or use various MIDI events to trigger processes.
Computer Skills for Musicians -5-

erik neuteboom wrote: Rush was a MIDI-controled progrock orchestra

Late shift again Erik?

erik neuteboom wrote: Yes .... ....

Erik Neuteboom - leader of the little green men (but only in the morning, after late shift)