Welcome to the music section. This section will provide you with the most important infos about computer music at basic level. This stuff is organized into a question-answer form, asking the common questions about this topic. If you got any other special question, just drop me an email, and if I will get more such a question like yours, I will place it here soon with my answer. Please do not ask the same question which is answered here, read this stuff before asking anything. There will be an intermediate level tips list for the musicians soon. Basic stuff
Q: What is computer music?
A: Computer music is music played by machine. This can be a simple analogue machine, a PC or any kind of machine which is capable of generating analogue or digital signal.
Q: What does it mean "analogue machine" ?
A: There are three basic types: generator, modulator and mixer. The generator creates a basic waveform, the modulator generates some effects and the mixer mixes various input waveforms into a final output. Analogue machines work with analogue signal (voltage). The value of the output signal represents the real signal value processed by the amplifier. No DAC (digital to analogue convertor) is needed. Analogue machines used to be controlled by CV - control voltage.
Q: What kind of waveform can a generator create?
A: The common envelope generators can generate sine, triangle, saw and square waves. You can specify the frequency and amplitude of the wave. The generators can play an other role too, they can generate waveform used by other machines as a modulator parameter (LFO- low frequency oscillator, MG- modulation generator)
Q: What kind of effects can be produced by a modulator?
A: There are some basic modulators: amplitude mod, frequency mod, phase mod and filters. Using these basic units we can produce some more complicated ones, reverb and chorus.
Q: What does it mean "digital signal" ?
A: Digital machines, such as a PC, can work only with digital data. This means that a waveform is stored in the computer's memory as a numeric array, called sample. These samples are not else than combination of ones and zeroes. If we wanna get back the analogue meaning of these values, we have to convert them via DAC. But be careful with terms! Machine using digital control signal does not mean that machine is digital. Digital signal can be used to control analogue machines with MIDI control unit. Fully digital machines work with samples (real or synthesised).
Q: How can I get those samples into the computer's memory?
A: By sampling an analogue signal. This means, that we can measure the value of the analogue signal after a constant time period, and store the immediate value as a numeric value. The quality of sampling depends on the length of time period between two measurements, the precision of the measuring unit, and the precision of the numeric values, in which our sample is gonna be stored. The most common values are 44100 Hz (we measure the signal value 44100 times during one second), and 16 bit signed precision (values can be between -32768 and 32767)
Q: What's the role of a human here, where everything is made by machines?
A: Don't forget, that machines are just capable of generating sound, which is far from "music" yet, and there is always a human behind all the electronic stuff. There are various ways how to control that sound, three of them are very popular: analogue sequencers, MIDI and tracking.
Q: I often hear people talking about this "MIDI" stuff, what it is?
A: MIDI - music instruments digital interface, is a standard by Roland, specifies the communication between instruments (or machines). MIDI specifies four main terms in communication: event, message, data block, data dump.
Q: Ok, but how can I make a music using MIDI?
A: People equipped with PC and sound card have got a MIDI machine on their sound board, called MIDI synthesizer. There are two basic types of MIDI synths: FM synth, and wavetable synth. Both of them generate sound in a different way, and you still need a sequencer to control the sound and events. People making music on PC using a sound-card and MIDI mostly use software sequencers, like Cubase, or Cakewalk. Professionals equipped with expensive MIDI hardware usually use hardware sequencers. Basically said, the sequencer is used for telling the machine what kind of sound should be played and when it should be played, so you can make music this way :)
Q: What's the difference between FM synth and wavetable synth?
A: The main difference is in generating the sound. FM synths use FM synthesis to create a sound. FM synthesis is using basic waveforms and Fourier synthesis, and the results is a synthetic sound, a sume of basic waveforms. FM synthesis should be used where nice synthetic sounds are needed (techno, new age and such). Wavetable is not else, than a set of samples, which consist of classical instruments, as well as different synths and sound effects. The standard General MIDI bank contains 127 instruments and a drum-kit. There two other standards in use: Roland GS and Yamaha XG. Wavetable synths need to have a sample memory containing all those samples. This memory can be a ROM (samples are stored in a read-only memory, user cannot change its content), a RWM (samples are stored in a read-write memory, user can replace some samples) and a RAM (samples are pushed into the random-access memory when they are needed, but they are stored elsewhere - on hard drive). Both FM and wavetable synths can be extended by DSPs (digital signal processor), which can create effects like reverb, chorus, filters, flangers, phasers, etc. Both FM and wavetable synths have got specified the maximum amount of sound played simultanously - this is called polyphony.
Q: What's that tracking about?
A: Tracking is a special way to make music using samples and a program called tracker. When using a tracker, samples are placed in the system memory, or if you have got a soundcard with sample RAM, they can be uploaded in there. The tracker works with large tables of alphanumeric data called patterns. There are many columns and rows in a pattern. Each have it's special meaning. The rows specify the time axis. If you put a note to the first row, this will be played sooner than a note in the fifth row. The column plays the role of a sound channel. Putting notes into the same row but different column will cause playing them simultanously. You will find kindda subdivision in each column. There is a space for 3 characters in the first position (look like ---), you can specify a note here (e.g. F-4, or F#7). The next position is called the volume column (some trackers can handle volume slides, panning effects here), and the third is called effect column. Each effect can be specified with it's type character and parameters. You can read more about this in a any tracker's user manual. You define the order in which the patterns are going to played, and when everything is done, save it as a music module. This module will contain all the samples you used, and all the pattern data with the order list. You should check out some links to find more about this topic.
Q: Which tracker is the best one?
A: There is no best one. Use the one you like the most. But there are two which are the most used ones: Fast Tracker by Triton (FT), and Impulse Tracker (the sequel to Future Crew's Scream Tracker 3) by Pulse (IT). These two look quite different but give you all of the tracker's features. Both of them have some pros and contras, in fact - if you 've started to used one of them, there is no serious need to move to the other one. Fast Tracker has got a nice user interface, a good sample editor, sampler and instrument editor, but the maximum amount of channels is limited to 32. Impulse tracker 's got a bit older look, a less effective sample editor, but in the other hand - it can handle more channels, can use the same sample with more instruments without loading it multiply into the memory, and NNAs, which can be very useful, when you are a less experienced user and cannot handle too many channels ;). Both can do the same type of effects, IT have resonant filters (but sound kindda strange). Summary: if you will be happy with 32 channels, and want a ease to handle, fast tracking tool - use FT. If 32 channels are not enough for you, and you used Scream Tracker before, try IT. There is a third one, which I did not mention yet, but 's still very popular - Buzz tracker. This is a new generation tracker, which works with software machines (generators, effect units, trackers). You can create a whole software synthesiser by connecting these units together. Very nice idea, fully visual tool, with software sequencer, and can communicate with any MIDI instrument (HW or SW).
Q: Where can I get those samples?
A: There are 3 common ways: create them for yourself, download them from somewhere, rip them from a module. Ripping is the easiest way, but has two flaws: 1. the sample will be not an original one (so you have to write credits for them), 2. the quality is done, and that's very hard to make it better... You can download samples from special sample sites from the internet, or from sample-CDs. This way has the same flaws than ripping, except the quality of samples on sample-CDs used to be quite fair. At the other hand, you have to pay for them :). Creating samples is the hardest way. You can use a microphone to sample vocals, real instruments, synthesisers, or use a software synthesiser to generate the sounds.
Q: Ok, I think I know enough about the technicals, so I can start making music. Do I need something else to know before I start?
A: You should learn some music theory - and figure out whether you are talented in music or not. Then you have to learn some tricks by practising. So good luck!