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Sampling has been with us more more than 10 years.Paul
Wiffen takes a retrospective look at its development and how it has shaped
the music of the last decade.
The first sampler I ever heard was on a 1980
record. The track Army Dreamers, from the Kate Bush album Never
For Ever. Although my ears told me that I was hearing a cello there was
no mention of a cellist, just a credit to one Geoff Downes on 'Fairlight'.
Whatever this mysterious device was, I wanted one!
For many years the name Fairlight became synonymous
with sampling (although it also boasted the first digital sequencer - Page
R and a variety of synthesis methods). To own one was the unfulfilled wish
of many, many musicians.
By today's standards, the original Fairlight was extremely limited. Its memory
was a mere 32k, its resolution 8-bit and the average sample rate a mere 16kHz,
giving results that would be sneered at by the average sampler owner today.
Listening to that Kate Bush track again, I was amazed at how rough that cello
sample sounded. But, the fact remains that it is still unmistakably a cello
rather than a synthesised copy, and that's what made the Fairlight so desirable.
It sounded like a bad recording, rather than a good imitation.
In 1981, the Fairlight was joined by the Em-u
Systems Emulator, which concentrated on sampling (leaving out the synthesizer
and sequencing functions to keep down costs). The Emulator widened the circle
of musicians who had access to sampling technology, but it was still the
domain of pop stars, large recording studios and highly paid session
musicians.
These early samplers both had rudimentary looping
(see Newslink Autumn 1990),but with only a few
parameters available for adjustment. Finding a usable loop was often more
a matter of luck than good judgement.
Similarly multi-sampling - the ability to place different samples on different
keys - was extremely limited, and samples were only recognisable as versions
of the sound source when played within a few semitones of the original pitch.
It wasn't long before some artists like Peter Gabriel were using samples
transposed down several octaves to produce long complex timbres, the like
of which had never been heard before.
8-bit resolution was the standard
for many years. Sampling was originally linear : the numbers stored in memory
were straightforward representations of the analogue signal fed in. Various
schemes were devised to encode these values to achieve greater accuracy,
such as
Delta-modulation.
This worked by measuring the difference between one sample and the next.
The theory was that you would normally have much smaller changes in value
between samples than the whole range available, so you could use the same
bit resolution to define a smaller change mere accurately. The 1984 Emulator
II was noticeably superior to its 8-bit linear predecessors thanks to this
kind of recording system. Other systems of sample encoding include Roland's
Differential Interpolation method (see David Marshall's article,
Newslink Autumn 1990). |
Sample memories grew too. The Emulator II, with
over half a megabyte of memory, allowed more than 17 seconds of sampling
at 26.6kHz unparalleled figures until, that is, New England Digital expanded
the Synclavier's capabilities to include sampling. Never ones to do things
by half, they introduced 16-bit resolution, a 50kHz sample rate and megabytes
of memory, limited only by the size of your budget (provided your budget
would buy you a large country house). There was one major drawback however
(apart from price), and that was that, for several years, sampling on the
Synclavier was monophonic.
At the (slightly) more affordable end of the
market a new use appeared for sampling. This was to use it as a technique
for encoding dedicated chips for drum machines. As far back as the original
Linn LM-1, manufacturers had used sampling to get realistic sounds into their
drum machines. Now both Linn and E-mu came out with drum machines that could
sample, so you could record and play back your own drum sounds before, during
or after creating the drum pattern that you wanted. Manufacturers of sampling
keyboards, meanwhile, started to introduce analogue components of synthesis
such as filters and envelopes.These allowed the sound to be reshaped in playback
and had a variety of uses.
First, poor quality samples could be cleaned up to some extent (or the shortcomings could at least be disguised) by filtering and changing volumes. Second, the natural envelope of a sound could be reintroduced after a sound had been looped (it would otherwise remain at a constant volume). This was particularly useful in sampling piano and other percussive pitched sources, where previously large amounts of memory had been needed to allow the sound to decay naturally. Now decay could be added to a loop, thus saving memory.
The Fairlight was not the first instrument to use recordings of real sounds. That distinction belongs to a British keyboard, the Mellotron, which dates back to the late 605. The Mellotron was responsible for the strings on tracks by King Crimson, Yes, Genesis, The Moody Blues and Barclay James Harvest (rumour has it you couldn't be a progressive rock band unless you had a Mellotron), as well as the flutes on Led Zeppelin's Stairway to Heaven. The difference between the Mellotron and the Fairlight was that, although both replayed recordings of actual instruments, the Fairlight used digital memory to store its recordings, as opposed to the clumsy tape replay system of the Mellotron (which had to rewind after 9 seconds). Another major advantage was that, with the Fairlight, you could make your own samples, instead of being stuck with whatever sounds the manufacturer had decided to record. |
But the third use was the most creative: samples
from the natural acoustic world could now be used as source waveforms (looped
or unlooped) for standard synthesis techniques. Instead of the sawtooth,
square or pulse waveforms which had been the basis of sound in analogue
synthesis, an infinite variety of waveforms became available.
This was one of the major features of the much
more affordable samplers that began to appear in 1985-1986. Whatever their
bit rate (some still used 8-bit, although most had moved up to 12-bit), whatever
their memory size (most had half a meg of memory), whatever their polyphony,
they all began to feature filtering and enveloping very heavily. The result
was machines that were much more versatile than their more expensive brethren
which may have had sample rates of 100kHz but whose features for modifying
the sound were still pretty limited.
Looping and multisampling became more sophisticated,
even on the cheapest machines. It was not uncommon for more than 50 samples
to be available across the keyboard (if you had the memory for them). Various
techniques began to evolve to make the tedious business of looping less of
a hit-and-miss affair.
The advantages of sampling percussion as against pitched instruments were obvious. Drum sounds needed less memory than strings or pianos, and they didn't need looping or multi-sampling. Sampling drum machines needed much less memory and were therefore much cheaper. Sampling drum machines were also the first area where 12-bit sampling was used. Although 8-bit companding systems were a significant improvement on 8-bit linear for sustained sounds, they weren't so hot on percussion sounds. The move to 12-bit meant cleaner, crisper drum sounds. |
Machines were either able to search for zero-crossing
points or other suitable places for click-free looping. Some could even create
a loop of the same length as the sound frequency to give a sort of autoloop
feature (the Roland S-10 was the first of these). Then crossfade looping
arrived, whereby the sampler could recalculate the waveform around the loop
point to smooth out any clicks or glitches.
The sampler became the subject of musical fashion
and there was a flood of N-n-n-n- nineteen type records, in which the sampler
was used more as an effect than as an instrument. Sampling features were
built into digital delay pedals. like the Boss DSD-3, so that a guitarist
performing live could play a phrase which would loop repetitively, whilst
he played a different part over the top.
The expense of RAM memory has always been a
major factor in the cost of samplers. In 1988 its price started to fall
dramatically.
At the same time, digital techniques for filtering came into their own, and
the analogue-based filter and envelope technology was replaced by more flexible
digital equivalents. This overcame a major drawback, which was that separate
outputs were, until then, forced to be monophonic because of the discrete
hardware required for analogue filtering on each voice. Digital technology
meant that samplers could finally have polyphonic separate outputs.
Visual editing - always available on the top
end systems which were essentially computers - became increasingly common
on more affordable samplers. Roland led the way in this respect. Ever since
the S-50, released in 1986, most Roland samplers have had a CRT output for
connecting a monitor, giving greater ease and flexibility of looping, mapping
and so on.
Samples began appearing in mainstream synths
with the introduction of the Roland D-50. Nowadays, there are few synths
on the market which do not have a wide variety of multi-sampled standard
acoustic sounds. Some, like the Roland U-20, are not so much synthesizers,
as sample players, using resynthesized
PCM technology
to give immediate access to a very accurate library. As a result, musicians
are no longer forced to turn to samplers for realistic acoustic sounds. Piano,
strings and brass are now to be found in the average synth's ROM.
This has had a major effect on the way samplers
have been used in the 90s (as a listen to the radio will reveal). Those who
still want to use them for recreating instruments have to look to the top
end of the market to achieve anything that is not already available on
sample-playing instruments. But the shift has been towards musical styles
where the sampler is used to reproduce whole sections of music, be it vocal
phrases, rhythmic grooves or other musical passages. These also need high
fidelity, stereo sampling and long record times, as developed for the Roland
S-770.
Sampling has come a long way in 10 years, from
primitive machines owned exclusively by the rich and famous, to a much more
highly developed technology that is available to the average musician. Sound
quality, facilities and programmability have increased as dramatically as
prices have dropped. Today's memory capacities are beyond even the wildest
dreams of the early sampler owners. So where does it go from here? Sampling
has grown closer and closer to hard disk recording (to which it is already
related by virtue of the digitization process). Roland's new DM-80 is an
example of this. Memory on hard disk (or optical) will become available for
real-time playback, and eventually the recording and performance applications
will fuse into a creative whole under the direct control of the musician
or producer. Roll on the next 10 years!
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