1114 Chapter 29
ports. The multiport MIDI interface, Fig. 29-18, is often
the device of choice for most professional electronic
musicians who require added routing and synchroniza-
tion capabilities. These rack-mountable USB devices
can be used to provide eight independent MIDI Ins and
Outs to easily distribute MIDI and time code data
through separate lines over a connected network.
29.3.2 Hardware and Software Electronic
Instruments
Since its inception in the early 80s, MIDI-based elec-
tronic musical instruments have helped to shape the face
and sounds of our modern music culture. These devices
(along with digital audio and advances in recording
equipment technology) have altered music production,
through the creation of one of the most cost-effective
and powerful tools in the development of music history
—the personal project studio.
The following is a sample listing of the many hard-
ware MIDI instrument types that are currently available
on the market.
The Synth. A synthesizer, Fig. 29-19, is an electronic
instrument that uses multiple sound generators to create
complex waveforms that can be combined (using var-
ious waveform synthesis techniques) into countless
sonic variations. These synthesized sounds have
become a basic staple of modern music and vary from
sounding cheesy, to those that closely mimic traditional
instruments all the way to those that generate rich, oth-
erworldly sounds that literally defy classification.
Synthesizers (also known as synths) generate sounds
and percussion sets using a number of different technol-
ogies or program algorithms. The earliest synths were
analog in nature and generated sounds using additive or
subtractive FM (frequency modulation) synthesis. This
process generally involves the use of at least two signal
generators (commonly referred to as operators) to
create and modify a voice. Often, this is done through
the analog or digital generation of a signal that modu-
lates or changes the tonal and amplitude characteristics
of a base carrier signal. More sophisticated FM synths
can use up to 4 or 6 operators per voice and also often
use filters and variable amplifier types to alter the
signal’s characteristics into a sonic voice that either
roughly imitates acoustic instruments or creates sounds
that are totally unique.
Another technique that’s used to create sounds is
wavetable synthesis. This technique works by storing
small segments of digitally sampled sound into a read-
only memory chip. Various sample-based synthesis
techniques use sample looping, mathematical interpola-
tion, pitch shifting, and digital filtering to create
extended and richly textured sounds that use a very
small amount of sample memory.
Synthesizers are also commonly designed into rack-
or half-rack-mountable modules, Fig. 29-20, that con-
tain all of the features of a standard synthesizer, except
that they don’t incorporate a keyboard controller. This
space-saving feature means that more synths can be
placed into your system and can be controlled from a
master keyboard controller or sequencer, without clut-
tering up the studio with redundant keyboards.Software Synthesis and Sample Resynthesis. Since
wavetable synthesizers derive their sounds from prere-
corded samples that are stored in a digital memory
medium, it logically follows that these sounds can also
be stored on hard disk (or any other medium) and
loaded into the RAM memory of a personal computer.
This process of downloading wavetable samples into a
computer and then manipulating these samples is used
to create what is known as a virtual or software synthe-
sizer, Fig. 29-21.Figure 29-18. M-Audio MIDISPORT 4×4 MIDI interface.
Courtesy of M-Audio, a division of Avid Technology, Inc.,
http://www.m-audio.com.
Figure 29-19. Bass Station analogue bass synth. Courtesy
of Novation Digital Music Systems, Ltd.; http://www.novation-
music.com.Figure 29-20. Yamaha MOTIF-RACK ES synth. Courtesy of
Yamaha Corporation of America, http://www.yamaha.com.