Transcript A brief history of MIDI

A brief history of Electronic Music
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Leon Theramin invents the Aetherophone in 1930
Synthesizers “began” in the 1940’s
They were initially as big as a house and cost
about as much or more
Evolved alongside recording technology
Early adopters are scientists and engineers as
much as musicians
Music created has narrow appeal
A brief history of Electronic Music
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Apmex in the US replicates Germany’s tape
technology captured in WW2
Artists begin making
tape based art, or Musique
Concrete, incorporating
found sounds (“sampling”)
in live performances (“DJ”)
around 1948
Pierre Schaeffer (1910-1995)
A brief history of Electronic Music
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Composers begin to use electronics to create
both prepared (recorded) and
performance-based “classical”
music
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Karlheinz Stockhausen
(1928-2007)
Early Analogue Synths
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ARP, Bob Moog (“Mogue”)
Modular (VCO, VCA, VCF,
LFO, envelope, etc.)
Based on CV
Monophonic
No way to save sounds
(patches)
Hard to keep in tune
No interoperability
Early Analogue Synths – cont.
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Oberheim invents polyphony (polyphonic) – four
simultaneous notes!
Streamlined design
Portable
Patch Memory
Brand specific inter-communication
Stacking
The need for standardization
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Like computers, synths needed a standard
(list standards)
1982 proposal of UMI at NAMM by SC
Many international revisions – MIDI: Musical
Instruments Digital Interface
1983 – first MIDI keyboards (Roland, SC)
What is MIDI?
MIDI is a communications protocol.
 MIDI is also a hardware specification.
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MIDI Communication Protocol.
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Universal. Everyone’s gear works together.
Expandable. New features can be added.
Transport control information.
Transport timing information.
Transport files.
The protocol is hardware independent.
MIDI Hardware
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Universal mixing and matching of gear
Master controller + keyboardless synth modules:
conserve space, layering possibilities
Automation & synchronization of gear for mixdown
or performance
Sequencing: timing correction, step based entry
Archiving of information
Typical MIDI messages
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Turning on and off notes
Expressing the velocity of each note
Sending program changes
Use of the sustain pedal and other controller,
such as pitch bend or modulation wheel
Timing relationships of all MIDI notes and events
MIDI is a serial transmission.
Each bit is sent one at a time.
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Parallel is faster,
more costly,
shorter cable runs
(printer)
Serial is slower,
cheaper,
longer cable runs
(modem)
Cables
Common MIDI Controller
messages - (7 bit)
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3 byte message.
Status bit.
1st data byte = 7 bit controller number.
2nd data byte = 7 bit controller value.
The protocol is based on two
types of bytes.
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Status bytes.
Data bytes.
Status bytes determine what kind of message
is being sent and where it’s going.
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Channel Voice.
Channel Mode.
System Common.
System Real Time.
System Exclusive.
Data bytes contain information.
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Note or controller number.
Note or controller values.
Attack Velocity.
Pitch bend values.
File data.
Example of a note on message.
(Channel Voice Message)
MIDI Controllers
(14 bit)
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Implemented as two 7 bit controllers.
3 byte message to send 7 MSB.
Another 3 byte message to send 7 LSB.
If fine adjustments don’t exceed 127, only the 7
LSB are sent.
If MSB is sent, LSB must also be sent.
MIDI time code (MTC)
(Systems Common Message)
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MTC is the MIDI equivalent of SMPTE.
Sent as eight 2 byte messages.
1 msg per each quarter frame of SMPTE.
8 X ¼ frame = 2 frames.
MTC updates SMPTE once every 2 frames.
At 30 frames per sec, 120 messages are sent.
That’s 1 update every 66.6 ms.
MIDI running status
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Does not send redundant status bytes.
This reduces the amount of time it takes to
transmit a MIDI message by 320 us.
Running status only works as long as you are
sending data that has the same status byte.
Changing the MIDI channel requires a new
status byte.
Before I can connect a computer to a
MIDI device, I have to connect it to a:
MIDI interfaces
What are my connection choices?
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Internal interface. (rare)
Com port. (obsolete)
Parallel port (aka printer port - obsolete).
USB. (most common currently)
FireWire. (quite common as part of an audio
interface)
Ethernet. (available - future?)
Wireless. (niche but available)
What are my MIDI interface
choices?
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1 MIDI in, and 1 MIDI out.
Multiple MIDI in, and Multiple MIDI out.
As part of an audio interface.
Direct USB to USB
Time code connectivity.
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SMPTE
LTC
VITC
MIDI Connections
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Max cable length is 50 feet.
Chaining more than 3 devices may cause timing
issues
Y cords are not allowed.
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Driving more than one input requires too much
current. ( spec is 5 ma.)
Multiple outputs to one input creates data collisions.
MIDI Controllers
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A MIDI enabled device capable of registering and
transmitting gestural information
Examples: note on / off, velocity, knobs, sliders, wheels,
pitch bend, breath, control changes, patch dumps, MIDI
Time Code (MTC), MIDI Machine Control (MMC), etc.
Originally keyboards, but today take on a wide variety of
shapes, sizes and applications
Some MIDI controllers are also sound generators –
some are not…
MIDI Controllers (cont.)
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This Akai MPK61 does not make any sound by itself - it
has no audio jacks. It is used for controlling other MIDI
enabled devices including software synths (Reason,
etc.) and hardware tone generators.
MIDI Controllers (cont.)
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Some keyboards such as this Korg Triton Studio are
synthesizers, samplers, sequencers and record digital
audio – all in one unit! And with the included MIDI
outputs on the back, can control other devices as well,
making them very capable MIDI controllers on top of
everything else.
MIDI Controllers (cont.)
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This device, known as a sound module, does not have a
keyboard, but has sound generating / synthesizing
electronics and audio jacks. It requires a MIDI controller
to tell it what notes to play.
MIDI Controllers (cont.)
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But not all MIDI controllers are keyboards, per se: This
one is called the Terpstra.
MIDI Controllers (cont.)
MIDI Controllers (cont.)
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…and don’t forget MIDI uses for:
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Theatrical lighting
Show control
Pyrotechnics
Video playback / manipulation
Ringtones
Video Games
Websites
Karaoke
Etc.