/---------shield---------------------\
/----------wire1---------------------\| |
| /--------wire2-----------------------\ ||
/------\ /------\ ||| |||
| 2 | max length 50ft | 2 |
| 5 4 | | 5 4 |
|o o | |o o |
\------/ \------/
midi out midi in
5-pin DIN plug
leave earth connected at
midi out only
Asynchronous:
1 start bit
8 data bits
1 stop bit
Baud rate: 31,250 Baud (+ 1%) _
(320 ms per serial byte)
Electrical interface level
5mA current loop
[Ref 1] Computing magazine March 90.
Our system of music has evolved according to what sounds pleasant to the human
ear, sounds need to be complex enough to be interesting but not so complex that
they appear dischordent. The most simple element of sound is a pure sine wave,
this is because the ear contains fibres tuned to various frequencies of sine
wave.
A sine wave has two characteristics:
- frequency, ie the number of times the sound moves backwards and forward per second, measured in cycles per second, or Hertz (Hz).
- Amplitude or volume.
Most real sounds, such as the sound produced by a vibrating string or air
column produce a more complex waveform made up of a sine wave plus a number
of harmonics of that frequency.
The frequency of musical sounds is perceived by the human ear on a logarithmic
scale. Each time the frequency is doubled the interval increases by an octave.
A triad consist of a bass note plus a third and a fifth this contains all
the harmonics upto 20.
