10.6

724Logic Pro Instruments
Granular synthesis
The basic premise behind granular synthesis is that a sound can be broken down into tiny
particles, or grains. In many respects, granular synthesis is similar to wavetable synthesis,
but it works on a much finer scale. This method is ideal for creating constantly evolving
sounds and truly unique tones.
Alchemy extracts sampled grains—2- to 230-milliseconds long—which can be manipulated,
reorganized, or combined with grains from other sounds to create new timbres. The effects
that result from this technique depend on factors such as the duration and amplitude
envelope of each grain, the degree of overlap or separation from one grain to the next, and
the pitch and pan position of each piece of sound.
If each new grain is extracted from slightly further into the sample than its predecessor,
playback of the resulting stream of grains in their original sequence, at the original speed,
essentially puts the pieces of sound back together to closely resemble the source audio
material. If you play back the stream of grains at a slower speed, separation (a small gap)
occurs between grains. If you play back the stream of grains at a faster rate, each grain
overlaps with the next one.
A number of interesting manipulations are possible using this synthesis method.
• Time-stretching. Grains can be sent out at a faster or slower rate than their
counterparts in the original sample, allowing faster or slower playback—without the
changes to pitch that occur with traditional sample playback. You can even “freeze” a
sample at a certain position by extracting multiple grains from a single point. On this
latter point, you could repeat a drum hit “grain” multiple times in a time-stretched loop
to create a different drum pattern, for example.
• Pitch-shifting. Modifications to the pitch of each grain allow you to vary the pitch of
a sample without affecting its timing. By modulating the pitch or pan position of each
grain, you can also create spatial and “blurring” effects.
• You can also scramble the order in which grains are played back to produce effects
ranging from mild fuzziness to extreme mangling.
A brief synthesizer history
Precursors to the synthesizer
The earliest seeds of modern electronic synthesizers began in the twilight years of the
19th century. In 1897, an American inventor named Thaddeus Cahill was issued a patent to
protect the principle behind an instrument known as the Telharmonium, or Dynamophone.
Weighing in at 200 tons, this mammoth electronic instrument was driven by 12 steam-
powered electromagnetic generators. It was played in real time using velocity-sensitive
keys and, amazingly, was able to generate several different sounds simultaneously.
The Telharmonium was presented to the public in a series of “concerts” held in 1906.
Christened “Telharmony,” this music was piped into the public telephone network, because
no public address systems were available at the time.