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midi
songs
I´ve
made up a small page with about 50 Midi-songs
I like. Most of the songs are programmed professionally and should sound
very good.
Ifni MIDI Music
Today's Hits has a big and very good archive of midi- songs.
about midi
MIDI means Musical Instrument Digital Interface. In ancient times it was
only used to connect synthesizers to hardware sequencers and computers.
Nowadays Midi is used to control effect units, mixers and even lightshows.
MIDI became a standard which is quite a shame. MIDI is very slow. You can
even use MIDI to transfer sample data (very slowly). Most of the time MIDI
data is only control data and doesn´t carry any sound data.
A computer´s soundcard (or other equipment connected via MIDI) recieves
the control data and uses it´s sound resources to play back. There
are 16 MIDI channels so you can play 16 different sounds, means that channel
1 controls a piano sound, channel 2 plays the bass, channel 10 is for drums...
. The result depends on the soundcard´s (or external equipment´s)
quality and perculiarity.
the sound(card)
Most soundcards come with an OPL 2 or 3 chip and something called "Wavetable"
or so. These Wavetable units contains samples of various instruments. The
OPL chip is a synthesizer. It contains no samples. It uses frequency modulation
to synthesize sounds. Unfortunately the sound quality (flexibility and
authentcity) depends on the numbers of operators. OPL 2 and 3 means 2 or
3 operators. Although 6 or 8 operators can produce terrific sounds, 2 or
3 operators sound quite bad. But OPL 2 or 3 is kinda standard, and now
let´s forget about it.
Wavetables at least use one sample for each instrument. Using only one
sample means that if it´s a C3 sample, playing a C4 (one octave
higher) will cause the soundcard (or sampler) to play the sample at double
speed. The pitch is one octave higher (good) and the length is half of
the original length (bad). Instruments and voices have characteristic areas
in their frequency spectrum (formants) which do not change (best example:
male and female voice). These formants will be pitched up too, and so the
sound will become unnatural (Mickey Mouse effect) (bad).
To avoid the bad effects one can use multisamples. This means that there
is not only one sample. Different samples are used for different pitches.
The more - the better. You play a scale but you hear the samples changing
(bad). To avoid this, one can use crossfades, means that there is no precise
split point but a smooth fading between the samples (good).
Another problem is the fact that the sound of an instrument changes when
it becomes louder. This problem can be solved by using multisamples too.
In this case multiple samples are "layered", means that you use samples
taken at different volumes and switch or crossfade them depending on the
key velocity. One can also use lowpass filters (they cut the high frequencies)
which open more and more when the velocity increases.
The biggest problem is the memory capacity. The more (multi) samples you
use the more memory you need. And: long samples need much memory too. If
you sample a piano tone from the beginning to the end it can be very long.
That´s what loops are for. Let´s stay with the piano. The attack
phase is very important to recognize the instrument. After that, the sound
doesn´t change very much. So we make a (short) loop of the sound
after the attack phase, fade out the volume and slowly close the
highpass filter. Purrfect! :-)
This was a very basic overwiew about the way soundcards and synthesizers
that use samples (and substractive synthesis) work.
BTW: Cheap equipment usually
comes with cheap D/A converters (digital/analog) so the sound will not
be as crisp, clear and powerful as more expensive equipment offers.
important
It can happen that a midi song doesn´t reset controller data at it´s
end, or the song´s or track´s volumes fade out, or you stop
the song while some controller data is not set to zero or a center value.
If the following song doesn´t have a reset at the beginning, volumes
may be set to zero, some tracks´ modulation may be enabled or pitch
may be shifted. If this should happen you have to do a reset. Here is a
very small ziped reset file. It contains
5 different midi files. GM and GS reset/on and a XG (Yamaha) reset. The
only thing to do is start the midi file and the reset will be done
within a second. You can also add a reset file to the beginning of any
song if you have a midi sequencing or recording program.
midi sites
(links)
Well... first of all I must recommend ResRocket.
You will find software that allows you to jam with other midi-musicians
all over the world. The only thing you need is basic midi equipment: a
keyboard and a GM soundcard or external equipment. The program includes
chat and a midi seqencer program. You talk, listen to the music, do your
own stuff and upload it into the current song. My user name is TheWanderer.
Maybe we´ll meet there.
Basic and detailed information as well about Midi can be found at http://www.midiweb.com.
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