Midi - MIDI is an acronym, standing for Musical Instrument Digital Interface - is a system, or a set of rules, defining how a Midi-compliant device (which can be a software device as well as a hardware one) behaves. Using Midi, commands can be sent to a Midi-compliant device, such as an electronic keyboard, to cause it to perform in a standard way, and thus give a predictable output.
The rule set defines, amongst other things, how many (and which) sound channels are used, and which instruments are included, and the order they appear in the list; for example, in General Midi, which specifies Channels Nos 1 to 16, and which numbers the instruments from 1 to 128, instrument No: 1 is a strange synthesised ping, No: 2 is a piano (an accoustic grand piano), No: 41 is a violin, No: 47 is a string ensemble (orchestral strings), No: 61 is a French Horn, . . . and No: 128 is a gunshot.
Within this rule set there are a number of variations relevant to specific devices; some devices use their own set of instruments, which may be similar to but not the same as - and in quite a different order from - those of the General Midi standard. In a Roland GS device, for example, all the instruments are much the same, and in the same order, but with different names. In an MT-32 device, however, everything is completely different . . . instrument No: 2 may be a piano but No: 41 is an echo bell, No: 47 is a "bellsinger", and No: 128 is a "jingle tune". This possible diversity means that a Midi File which includes the instruction "Play instrument No: 41" may not always have the intended effect! Luckily, most devices can be set to behave as a General Midi device, and therefore most Midi Files are General Midi Files, and assume that they are going to be fed to a General Midi device.
My own device is a Soundblaster card ... specifically, a Creative AWE 64 card. It contains a full General Midi set of sound patches in an on-board chip, and they're not bad. Things sound quite good with it; in general, the strings sound like strings, the brass sounds like brass, the woodwind sounds like woodwind, and so on - though it could be improved!
If you want to check what your "device" is doing, download the Midi File Check Device - click on download Check Device now - and play it (preferably using the Noteworthy Player). It plays a series of two-octave C major scales using the following instruments in sequence: a piccolo, a clarinet, a French horn and a bassoon, and then a whistle, a cor anglais, a baritone sax and a tuba, and finally orchestral strings (twice, an octave apart). These are the instruments I use mostly in my Midi Files; with my AWE 64 they sound fairly realistic (if you want to hear what they sound like on my machine you can download and play any or all of the 1.6MB WAV File Scales.wav, the 600KB MP3 File Scales-22kbs.mp3, or the 100KB MP3 File Scales-8kbs.mp3).
The Midi system is by now pretty ancient - it might be done differently were it designed from scratch today - but because it is quite successful it hangs on.
When keying stuff in I generally assign suitable instruments to the various parts, and I usually try to turn the piano reduction accompaniment into something more like an orchestral accompaniment (with strings, woodwind and brass, and so on) so that I get used to a sound vaguely like I'll experience during the actual performance (though obviously I could leave it as a piano!). And so that the several voices stand out more clearly I invariably use instruments - rather than "voices" - for them ... thus, a piccolo or whistle for the sopranos/trebles, a clarinet or cor anglais for the contraltos/altos, a French horn or baritone sax for the tenors, and a bassoon or tuba for the basses.
I also try to model my effort on some real performance of the Work, so that it bears some resemblance to how one will actually sing it - well, to how some professional Choir has sung it, at least! This means fairly carefully implementing all the dynamic and tempo changes of the real thing.
I can make audio tapes of the resulting output from "Session", and I listen to these whenever I can - in the car, while doing the washing up or ironing, while out jogging. I find that being able easily to hear my part helps me drive it into my memory, and the more times I do it the better I know the piece.
Of course, not only can I make Tenor-emphasized versions, suitable for me, but I can just as easily make versions emphasized for any of the other voices. And this I do, and many of my fellow Singers have in the past expressed appreciation for the tapes I have provided for them.
And now ... I thought it would be a useful service to the world to make the basic Midi Files available to anyone who needed them ... and this I now do - see the Composer Index below. You should bear in mind, though, that when you play them on your computer you won't necessarily have a wonderful musical experience! The problem stems for the combination of what a Midi File is - a sequence of instructions to your computer (or some other Midi-aware chunk of hardware) to generate the sound using the supplied sound-defining data - and the nature of that data.
The instructions follow the lines of: "Pretend to be instrument No: 41 (in General Midi this is a violin); at a selected tempo, play a note corresponding to a quaver at the pitch of C sharp an octave above middle C, with just a smidgeon of attack and with quite a long decay, at a volume corresponding to the dynamic forte". The hardware can operate fast enough under its controlling program do this in a microsecond or three, whereupon, and while that note is still sounding, it takes in and acts upon the next instruction, and so on. In this way the instructions can tell the hardware to make noises like all the instruments in an orchestra, all at the same time. It can sound quite realistic, but ...
... sometimes the only available data is effectively no more than a formula that tells the hardware how to synthesise a waveform that's generally like that emitted by some chosen instrument. The operative word is "generally"; if it's not done well - and it rarely is - the result sounds just like ... well, a computer!
The alternative is for the hardware to have available to it (usually stored in it) the actual sound from a real instrument (or whatever; a helicopter, a gun shot, a hand clapping, whatever) - a "sample" of the sound - and to use that sample, suitably modified (up or down in pitch, say) when required. So when instructed to be a violin the program running the hardware fetches the appropriate violin sample - there may be several depending what the note's pitch and dynamic is - and uses that to generate the required sound. And that can sound pretty good - even almost indistinguishable from the real thing - if the samples are good and the controlling software does a good job. The trouble is, it all depends on the hardware, the software, and the data. On your computer it may sound fine ... but it may not. In either case remember that it's nothing to do with me!
Another crucial factor is the care put into generating the sequence of Midi Instructions to make the most of how the sound can be produced. Midi Instructions can be formed in two main ways. One involves using a Notation Program the primary purpose of which is to provide a representation, on the computer screen and on paper, of the music in standard notation form; lots of black and white blobs, with or without tails and joiny-up bits, littered over sets of five thin horizontal lines (the staff). Noteworthy Composer is a Notation Program; one of the best - and most expensive - Notation Programs is Sibelius. The other way involves using a Sequencer Program the primary purpose of which is to provide almost infinite control of exactly what sounds come out of the chunky hardware bits. Session (and its recent relative Studio) is a Sequencer; a rather better-known one is Cubase. Generally, Notation Programs have some Sequencer capabilities (and can output their Files not only in their own internal File Format but also in the standard Midi Form), and Sequencers have some Notation abilities. If you want to see it you use Notation software; if you want to listen to it you choose a Sequencer. I find it easier to use Noteworthy Composer to enter the notes into the computer, and Session to adjust the Midi File output subsequently - which is at least one reason why my Midi Files sometimes sound a bit ... computerish.
You may be interested to know that many modern composers do their initial composing using Sibelius - examples being, I understand, John Rutter (former Director of Music at Clare, Cambridge, and a very well-known modern composer) and the ex-Beatle Paul McCartney.
Last updated by John on 3/Apr/05