Music and The Home Computer - An Introduction to MIDI for Pianists
John M. Zeigler, Ph.D.
he inherently mathematical basis of music led to a very early interest in generating, composing and listening to music on personal computers. With the development of the MIDI (Musical Instrument Digital Interface) specification in 1983, it became possible to connect all kinds of musical instruments directly to a personal computer or to have the computer "emulate" (produce the sound of) such instruments. MIDI is a standard that manufacturers of both hardware and software can use to allow such musical devices to "talk" to one another and to personal computers. If you use composing or recording software, or the great majority of music learning packages of all sorts, you have probably been using the MIDI capabilities of your computer. Even if you don't have an interest in these types of software, if you listen to the piano music found here on The Piano Education Page, you are using the computer's MIDI capabilities to play these MIDI (.MID) files. Because MIDI capability is so important to those with an interest in music and available to almost everyone who has a PC, we'll devote this article to a non-technical discussion of MIDI on the personal computer.
The roots of the MIDI specification lie in the earliest days of "synthesizers." It turns out that it is relatively easy to design electrical circuits ("oscillators") that, when given a broad range of frequencies as an input signal, will output a single, or nearly single, frequency ("tone"). The tones produced by these circuits don't sound very musical, because real instrumental musical tones are not single pure frequencies, but complex mixtures of the base frequency (pitch) with other overtones (frequencies at multiples of the base) and harmonics (different, resonating frequencies). However, by connecting together several oscillators, operating at different frequencies, one can "add-in" the harmonics and overtones to get musical notes (a form of "Fourier synthesis").
Depending on how many oscillators were connected together and what their oscillating frequencies were, it was possible, with a lot of work, to do a creditable job of imitating the timbre ("sound") of almost any musical instrument on a synthesizer. In the analog synthesizers of the 1960's and '70's, the mixing was done by connecting the oscillators together from a central patch panel using electrical cords ("patch cords"). Thus, the specific configuration of cords on the panel necessary for a given instrument timbre became known as a "patch map." It took many oscillators linked together manually to produce a given tone and timbre in the analog synthesizer. Thus, even the simplest synthesizer recording took months of work to produce.
Many of us still remember the remarkable recordings of Bach works by Wendy Carlos, done on one of the first Moog synthesizers (the predecessor of the digital piano). The album, "Switched On Bach", which appeared in the early 1970's, shows on the cover a man in Bach era dress and powdered wig standing in front of a massive synthesizer. When it appeared, critics characterized "Switched On Bach" with words like "brilliant", "revelatory", and "awe-inspiring". This was all done on a synthesizer with a tiny fraction of the power present in even the simplest digital keyboard of today.
After the IBM-PC appeared in 1981, it wasn't long before musical hobbyists began trying to use the PC to reduce the amount of work required to create music on the synthesizer. Each individual had his own home-built solution, which was incompatible with almost everybody else's solution. To address these problems of cross-compatibility of electronics and file types, the MIDI specification 1.0 was put forth in 1983. The original MIDI specification has two basic components: a set of directives which define the electrical characteristics of connections for MIDI devices (cable type, what signals are on what pins, and so forth) and a data format for MIDI signals sent and received by MIDI devices connected to the computer (or any other digital device). One important element of the MIDI electrical specifications is that it allows MIDI devices to be "daisy-chained", making it possible to connect multiple MIDI instruments to each other and to a single MIDI port on a computer. I'll spare you the details here, but if you're an electrical engineer or programmer and really want the gory details of how MIDI works, you can find that and lots more at the MIDI Manufacturer's Association Specifications page. The What Is MIDI? page and pages linked on it provide a slightly more approachable version of that information.
Later, the General MIDI specification defined a standard way that specific instrument timbres could be accessed by software and the minimum number of channels (16) that could be used simultaneously with different timbres. A total of 128 different instruments and sound effects (e.g. gunshot, rain, echoes, and many more) are defined in the General MIDI specification. Most MIDI keyboards can play the full 128 General MIDI "voices", which include Acoustic Grand Piano and less common ones like the Ocarina. A full set of note pitches and timbres specific to a given instrument comprises a specific voice and is usually referred to as a "patch map." With the right software, you can easily use (and probably already do!) the MIDI capabilities of your system. Usually, it's trivially easy in software to switch the MIDI patch map to change instruments (voices) for a given MIDI sequence. For example, in General MIDI, choosing the timbre (instrument) is simply a matter of asking for the desired patch map (still called that, even though the patch cords and patch panel don't exist on the computer or the keyboard) in your software. The Acoustic Grand Piano patch map is number 000 (i.e. the default instrument) in any device which supports General MIDI; if you want harpsichord, you ask for patch map 007; for pipe organ, it's 019; for ocarina, it's 079 and so forth. If you think Bach is different on an acoustic piano vs. a MIDI keyboard, you'll find that listening to Bach MIDI files voiced on the ocarina is a real trip!
More feature-filled MIDI keyboards support not only the General MIDI specification, but, in some cases, extended versions of the original specs. Because General MIDI is so widely supported in hardware and operating systems, almost all software programs which use MIDI support General MIDI, at least. Some programs also support the various extensions to General MIDI.
Virtually all personal computers provide built-in support for at least General MIDI on their sound cards and in their operating systems, even though some no longer provide a MIDI port to connect to on the sound card. For most older computers, this MIDI port is the "joystick/MIDI" port on the sound card (the same card on the back of the computer that you connect your speakers to). You connect your MIDI device to it using a MIDI cable.
If you're buying a computer that you plan to use for musical purposes, you'll want to verify that the sound card has a MIDI port. Some sound cards (e.g. many of those from Creative Labs) have MIDI built into the sound card's DSP chip, but don't provide a connector to it. These must be supplemented with a small port that plugs into the sound card. If your computer doesn't have the MIDI interface on the sound card at all, you can add MIDI capability easily, using a USB-to-MIDI cable, for under $40.
The instrument end of the MIDI cable has MIDI In (meaning the signal coming from the computer) and MIDI Out (the signal going back to the computer or to the MIDI In port of another MIDI instrument). Most people who have problems getting a MIDI instrument to work simply have misconnected the cables. If your MIDI instrument isn't working properly, just switch the cable connections at the instrument. If that doesn't work, you may need to change MIDI In or MIDI Out drivers from your Windows Control Panel. Usually, you can get a MIDI instrument working with the computer in a matter of minutes using these techniques.
A full discussion of the many types and models of MIDI instruments (both keyboard and non-keyboard) available today could easily take up an entire book. As the technology develops and the market grows, they are sold at increasingly reasonable prices. For pianists, the ones of most interest are digital keyboards and digital pianos. Even the most inexpensive keyboard, at around $150, has a full set of MIDI capabilities. What cheaper keyboards may lack is pedals, a full 11 octave span, and velocity sensitive, weighted keys. Keyboards lacking these features may be useful for beginning pianists for a limited period of time, but will embody too many compromises to be used for long-term training on the acoustic piano. If you're thinking of buying a keyboard or digital piano and have any thought of connecting it at some time to a computer, make sure that the keyboard has MIDI ports (MIDI In and MIDI Out). Most, but not all, keyboards and digital pianos have MIDI capability and ports.
As one moves to more expensive keyboards and, finally, to digital pianos, the number of compromises becomes fewer and fewer. For example, Roland's top-of-the line digital pianos have what Roland calls progressive hammer action w/escapement, sympathetic resonance and half-pedaling capabilities. Pianists will recognize these as important elements of providing the digital piano with not only the sound, but much of the "feel" of the acoustic piano.
The best digital pianos may not be exact "equals" of the best acoustic grand pianos in their feel, but, for a given amount of capability, they are cheaper to buy and own and much more portable. When one considers that the price of an acoustic piano is increasing steadily due to increased labor and material costs (not including the cost of maintaining it after purchase), while the price of digital pianos is dropping rapidly for a given amount of capability, it seems that digital pianos will become increasingly attractive for those who wish to take lessons on or play the piano. A recent piano marketing report summary indicates that MIDI-based digital pianos already outsell acoustic pianos worldwide, with most of the digital piano sales in the U.S. For a more extensive discussion of the pros and cons of using digital pianos and keyboards in piano lessons, see our Buying and Maintaining a Piano and Digital Pianos and Keyboards in Teaching and Learning pages.
It's great to have a way for the computer to communicate with and emulate musical instruments, but it wouldn't be much use if there wasn't a way to create files that could be stored and read or listened to later. The MIDI specification also defines a format for computer MIDI files that allows a computer to read, play, produce and manipulate MIDI files. In the end, it's the standardized nature of MIDI files that makes them useful to most of us.
Because the MIDI specification works by responding to commands which specify
"voice", note pitch, length, dynamics and so forth, MIDI files (.MID)
are actually sequential compilations of MIDI instructions of that sort. That's the
reason they are often called "MIDI sequences." The computer can turn MIDI
sequences (you can find about 700 such in our
Room page) into sound that comes out of the speakers because the
digital signal processor chip on the sound card and the operating system understand the MIDI
Note that MIDI files have no actual "sound" embedded in them. A MIDI file is a set of instructions to produce music, not a computer representation of the sound of the music. MIDI files are more like the score of a piece of music than the music itself. So, the result of playing a MIDI file depends to a sizable degree on the hardware present in the computer. In this respect, MIDI files differ fundamentally from waveform files (.WAV on the PC) or compressed versions thereof (.MP3, for example), which are digitized samples of actual sound recorded 11, 22 or 44 thousand times per second in each of two stereo channels. Because they contain instructions for playing rather than actual sound, MIDI files are typically less than a tenth of the size of corresponding waveform files, and are widely used on the Internet for music. If you'd like to learn more about these differences, see my PEP article, Creating Sound and Music on the PC.
It follows from this discussion that the computer can easily adjust the speed at which a MIDI sequence is played, without changing the pitch, while it's much more difficult for a CD, which carries the digitized sound in a compressed waveform format. Thus, typically, the CD is used in listening to recorded music, while a computer CD-ROM with MIDI files is used for teaching and learning.
This easy manipulation of MIDI by the computer is part of what makes having a MIDI-compatible keyboard or digital piano so attractive in teaching and learning environments. There are many music and piano programs which support a MIDI keyboard or are even designed around one. An overview of some of the most established packages for teaching and learning various aspects of music and piano can be found in my article, Music Teaching and Learning Software. Many more newer programs which use MIDI to advantage are reviewed on our Piano and Music Software Reviews page. Virtually all of these programs either will use or require a MIDI keyboard.
Chances are that, if there is something music-related that you want to do on your PC, you can find software to do it. Chances are even greater that it will use MIDI in some or all of its parts. Some of the things that can be done using MIDI-capable software (including commercial, shareware and freeware software) on a PC or Macintosh are:
This list is incomplete, but should give you a sense of just how important MIDI is to all kinds of musical activities on the personal computer these days.
Because MIDI capability is near universal on computers and one can accomplish nearly anything musical with the right software and a digital piano or keyboard, many piano teachers now have computer-based teaching labs in their studios. These provide students with drill and knowledge that is hard to work into the limited time of a weekly lesson. The student still gets his lesson time with the teacher, but learns a lot more faster with the help of the MIDI keyboard and computer. Our article for teachers, Establishing a Studio Computer Teaching Lab, has an extensive and detailed description of how to set up and run a lab and some suggestions for what can be done with it. This article may also be of interest for the home musician who wants to explore using the PC to make music.
Note that you don't necessarily need a MIDI instrument at home to listen to or compose MIDI files on the computer, though having one certainly makes composing (and many other elements of learning and enjoying music) easier. We are privileged on PEP to have an excellent article, A MIDI Sequencing Tutorial, written by Robert Finley, one of the world's experts on MIDI performing and composing. I recommend it to you if you would like to explore that aspect.
The long-standing support for MIDI capability on both the PC and Macintosh means that just about any personal computer (PC or Mac) of the last ten years or so can be used for experimenting with MIDI music. A few may need an inexpensive add-on MIDI card (mostly older Macintoshes and a few older PC's), but most newer PC's have all the hardware you'll need at the computer end. These days, you can buy a powerful new computer for under $500. You can find a basic MIDI keyboard for under $150, either alone or bundled with learning software like the eMedia Piano Method. If you want a better, more powerful digital piano, you'll find that you can spend more for it than the computer, though it's a good use of money, if you're already a reasonably accomplished musician. Usually, hooking up the computer to the instrument and installing necessary software/drivers is simple and virtually fool-proof.
One valuable resource for computers and MIDI instruments is, interestingly enough, garage sales. Since MIDI capability isn't very demanding on the computer's hardware resources, an older computer picked up at a garage sale for $20 or so will, in most cases, be more than sufficient for MIDI experimentation. Similarly, serviceable MIDI keyboards and even digital pianos can be obtained very cheaply at garage sales (usually, well under $100). If you like shopping garage sales and can spend 3 or 4 half days looking around, chances are extremely good that you can get everything you need, including software, for under $200. At that price, just about anybody who would like to learn the piano or try composing can afford it. In buying used hardware, just make sure that you get all the cables, manuals and software that go with the hardware, since it can be more expensive to replace missing items than to buy the hardware used. Have the seller verify for you that the device is working properly. If the computer or keyboard is missing manuals, you can use that deficiency as a negotiating point for a lower price, then download the manuals in PDF format from the manufacturer's web site.
With all the hoopla that has gone on for several years over MP3 music and players (e.g. the iPod), it's easy to lose sight of the older (and much more versatile) MIDI-based musical world. The MIDI specification for the personal computer has the made the computer a tremendous tool for teaching, learning and enjoying music. This will only become more apparent as the power of computers and digital pianos increases at the same time as the price for that power decreases. Digital pianos already outsell acoustic pianos worldwide and the margin is widening. These "new" tools open new vistas for teaching and learning which I believe we would be foolish to ignore, for pedagogical, technological, cultural and expressional reasons. I hope this introduction gives you a sense of how important MIDI is for musically-inclined people and what you can do with the MIDI capability you already have. If you're into music, MIDI is your friend. Use it!