Date: Mon, 15 Nov 2004 19:14:20 -0500
Subject: Re: [CB] [CB Digest]
From: Timothy J Tikker
On Monday, November 15, 2004, at 06:51 PM, List Server
wrote:
> This "amplification" effect seems most pronounced when a
soft contrabass
> instrument is doubled at the octave (or fifteenth) by
another instrument.
> Can anyone explain how this works?
Could be a question of difference tones. When a pitch an
octave higher is added to a given pitch, the difference between their
vibrations is the same as the lower pitch.
Example: If you played a low A which is 110 vibrations per
second, then add the upper octave to it, which is of course twice that,
i.e. 220 vps, then the difference tone between the two pitches is:
220
- 110
= 110
- Tim Tikker
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Date: Tue, 16 Nov 2004 08:00:31 -0500
From: Lawrence de Martin
Subject: Re: [CB] Lowest Notes
I'm with Gregg. A 32' closed pipe is lower than any other
instrument except the biggest bar of the Marimba Eroica; and the organ
is the only bass instrument powerful enough to project in that register.
Mr. Guzis confirms my contentions about bass hearing, but does
not complete the syllogism. We obviously can hear below 1Hz, as
that is 60 bpm, a medium tempo; in fact, we can hear events that happen
once, like a gunshot. This has an effective frequency of zero.
Fourier mathematics shows that the repetition rate (rhythm) of a
tone burst (staccato bass notes) is a frequency component of the
signal. The fluttering he describes is generating a "note" by
repeated lingual transients amplified by the horn - and he hears it.
Continuous tones of 8Hz can be heard, but they were excluded
from "common knowledge" of the extent of human hearing through a bad
assumption by Dr.s Fletcher and Munson. Their large scale survey
of hearing utilized headphones, asserting that all hearing took place
through the pinnae. Later studies using loudspeakers conducted by
Robinson and Dadson and Churcher and King showed considerably more bass
extension. Lower sounds are perceived using the entire body as a
conduit to the mind.
As the frequency goes down, there is a gradual and overlapping
transition between perception of note (frequency) and perception of
rhythm (time). One of my crusades is proving that humans hear
phase differences, which is why bass staccato notes are not accurately
reproduced by loudspeakers. They all distort time, which is
perceived as both rhythmic and pitch errors by people who listen to
music more than they listen to speakers.
Of course, organs can't produce bass staccato. That is the
domain of percussion, plectrum instruments and human wind chests. The
latter is one of the most precious sounds in my universe.
Larry de Martin
Bassophile
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From: "Eric J. \"Rick\" Allen"
Subject: Re: [CB] Big Pipes
Date: Tue, 16 Nov 2004 10:36:21 -0600
> but I humbly submit that a 16 Hz "tone" is probably
felt as a pulsation rather than heard as any sort of tone. I
recall that
> Audsley, who wrote at the time of the construction of
the instrument in Centennial Hall in Sydney was quite skeptical
of the musical value of a 64
> foot stop.
>
> Cheers,
> Chuck
Who cares? It's cool just to have one! :-D
Perhaps this next statement is being made out of ignorance on my
part, but can you imagine the amount of air required to move a column
of air that size? :-O
Eric in MN
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Date: Tue, 16 Nov 2004 09:36:23 -0800
From: "Chuck Guzis"
Subject: Re: [CB] Lowest Notes
On 11/16/2004, Lawrence de Martin wrote:
>Mr. Guzis confirms my contentions about bass hearing, but
does not
>complete the syllogism. We obviously can hear below
1Hz, as that
>is 60 bpm, a medium tempo; in fact, we can hear events that
happen
>once, like a gunshot. This has an effective frequency
of zero.
Mr. Martin, thank you very much for your detailed
discussion. You certainly bring up some interesting points.
I think the problem is one of semantics; "hear" describes a wide
range of sensations. If I set my metronome to 120 bpm, am I
hearing a 2Hz tone or just a repetition of a higher frequency
event? When I drive to and from rehearsal, it involves a 600 foot
change in altitude; when my ears "pop" am I hearing an extremely low
frequency "tone" (it consists of no higher frequency components)?
Or is a tone for the ears something akin to what a movie is for
the eyes? Our persistence of vision integrates a sequence of
images into a continuous whole, provided that the images are presented
to our eyes quickly enough. A "movie" viewed at 1 frame per
second is just a sequence of discrete images--a slide show and no
longer a movie.
When does a musical hum become an unmusical rattle or
thumping? At what point is it meaningless to talk about a very
low frequency "tone"?
Best regards,
Chuck
---------------------------------------------------------
From: "Eric J. \"Rick\" Allen"
Subject: Re: [CB] CB Flute Notes -- My guess
Date: Tue, 16 Nov 2004 11:16:58 -0600
> This "amplification" effect seems most pronounced when a
soft contrabass
> instrument is doubled at the octave (or fifteenth) by
another instrument.
> Can anyone explain how this works?
>
> Jay
As stated in the subject line, this is my guess...
It seems to me that if 2 high-pitched instruments (flute,
harmonica, etc.) can produce sub-tones (try tuning 2 beginning flutes
in high register! Or an out-of-tune-with-itself harmonica!), then
a virtually subsonic instrument, which may not have a strong overtone
series in and of itself (my guess is that a CB flute would fall into
this category -- help me here, wind players!), may be enhanced
substantially when other instruments are "filling in" the 1st and 2nd
[and other] harmonics of the CB instrument's overtone
series. In fact, perhaps the other instruments, in combination,
produce an otherwise-unheard subtone, which in fact is the equivalent
of the CB's pitch!
When Mozart and the other Classical-era composers had the bass
and cello parts doubled, it wasn't just for ease of writing -- the
parts sounded stronger because they were teaming up!
Solo string bass in low register is OK ("Jaws Theme", anyone?),
but when another instrument complements the sound (what a great
duo: the bass trombone and the string bass! Cellos, too, of
course), there the sum is so much greater than the parts, IMHO.
Does this make sense?
Eric in MN
String bass player who loves the punctuation of the bass
trombone, plus the complement of the celli whenever possible! :-)
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Date: Tue, 16 Nov 2004 11:25:05 -0800 (PST)
From: brwmeistr
Subject: Re: [CB] Lowest Notes
--- Chuck Guzis wrote:
> When does a musical hum become an unmusical rattle or
> thumping? At what point is it meaningless to talk
about a
> very low frequency "tone"?
Consider the "sound" of the launch of the space shuttle, the
overpressures felt in the chest with a frequency of about 2 Hz.
There were other massive sounds produced as well, but that frequency
was (for me) the most intense, and was definitely felt, rather than
heard.
Paul Gennrich
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Date: Tue, 16 Nov 2004 11:51:39 -0800
From: Craig
Subject: Re: [CB] Lowest Notes, etc.
A 32' closed pipe has an effective length of 64'.
I am seeing confusion between the simple perception of an
acoustic event (explosion, metronome beat, drum beat, 64' 'note', etc.)
and the assignment of musical qualities -- especially pitch -- to the
event in question. A single event such as a gunshot, thunderclap or
drumbeat, consists of a burst of broad-spectrum noise. That is, many
frequencies are present. Of course, what makes such events of interest
to us is the fact that the spectra are 'weighted' toward low
frequencies. ;-)
For Rick Allen in 'Big Pipes': contrabass pipes do indeed
require large amounts of energy to move the requisite volume of air. As
do contrabass wind instruments generally, which is chief of several
reasons why elementary school bands do not have tubas. (Although I
wanted to play contra-alto clarinet from the time I first saw one,
which was in my jr. high school days...)
For Chuck Guzis in 'Lowest Notes': You hit the nail on the
proverbial head (a burst event, containing a spectrum of higher
frequencies). Most people cannot discern pitch below about 30 Hz, as
distinct from simply being able to perceive the sound. I know I have to
resort to harmonics to tune the low B on my 5-string bass guitar, which
checks in at about 31 Hz.
For Rick Allen in 'Flute Notes...': What you describe is the
'resultant' effect, used in organs to synthesize bass notes without use
of large pipes. It is likely that this psychoacoustic effect is
responsible for the 'amplification' of certain bass notes under certain
conditions.
Craig
---------------------------------------------------------
Date: Tue, 16 Nov 2004 12:04:29 -0800
From: "Grant Green"
Subject: Re: [CB] Lowest Notes
>> When does a musical hum become an unmusical rattle or
>> thumping? At what point is it meaningless to talk
about a
>> very low frequency "tone"?
The lowest frequency that you perceive as a "pitch" varies from
person to person. Those of us who actually listen and pay attention to
that end of the spectrum tend to hear
pitches in frequencies lower than other people. Tuba players
can generally tell the difference between A0 and Ab0, while piccolo
players may have trouble recognizing the frequency as an actual note.
I don't know if there is a theoretical minimum frequency that
could be perceived as pitch - this is a function more of your nervous
system than of acoustics. However, the fact that we don't find some
tempos (tempi?) or rhythms "dissonant" with particular keys suggests
that ultra-low (rhythm) frequencies do not function as pitches for us.
Otherwise, we should find that, for example, that 122.7 bpm (= C-3)
sounds good in C major, but not in F# major.
Perhaps it does. Here's an experiment we could try: take several
pieces of music, each in a different key (but a single key throughout
the piece). It would be best to use music that is not familiar, so that
you won't have a preconceived idea of what the proper tempo should be.
Transcribe each into a MIDI file. Have someone play back each file at a
variety of different tempi, where the tempi correspond to pitches C-4
through C-3 or so (let's call those "sub-pitches"). Make sure they pick
sub-pitches that correspond to notes that are both consonant and
dissonant with the keys of the music you've picked. It is best if your
collaborator calculates and selects the sub-pitches, so that you can
listen without being influenced by your ability to count beats. Listen
to each piece at several different tempi, and rank them in order of
preference from best to worst. Since we're looking for consonance,
"best" should not be the
piece/tempo combination that sounds like it has the most tension. Then,
unblind your study: see if the tempi that ran
ked highest were closest to consonant intervals, and if the
tempi that ranked lowest should be dissonant intervals. Report back :-)
As an alternate, we could take a number of recordings, extract
the tempo and key information, and see how often the tempo corresponds
to a consonant "ultra-root" frequency. Alternatively, if you have
multiple recordings of the same piece (I think I have at least four
different versions of "The Seasons"), see how much the tempo varies
from interpretation to interpretation, and rank order the ones you like
best. Then, compare the tempo and the key, and see if they coincide.
Anyone game?
Enjoy,
Grant
--
================================
Grant Green Contrabass.com
Sarrusophones & contrabass winds
**NOTE NEW ADDRESS**
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--
---------------------------------------------------------
Date: Tue, 16 Nov 2004 12:15:14 -0800
From: "Grant Green"
Subject: Re: [CB] Lowest Notes, etc.
>I am seeing confusion between the simple perception of an
acoustic
>event (explosion, metronome beat, drum beat, 64' 'note',
etc.) and the
>assignment of musical qualities -- especially pitch -- to
the event in
>question. A single event such as a gunshot, thunderclap or
drumbeat,
>consists of a burst of broad-spectrum noise. That is, many
frequencies
>are present. Of course, what makes such events of interest
to us is
>the fact that the spectra are 'weighted' toward low
frequencies. ;-)
Yes, exactly. If you take a single "impulse" event, like a
gunshot, it takes a lot of Fourier components (each corresponding to a
frequency) to approximate the impule waveform. Your ear hears the
components as overtones/harmonics/timbre elements of the wave, and
picks up more of the higher frequencies - the ear is naturally more
sensitive to higher frequencies than lower.
>For Rick Allen in 'Flute Notes...':
>What you describe is the 'resultant' effect, used in organs
to
>synthesize bass notes without use of large pipes. It is
likely that
>this psychoacoustic effect is responsible for the
'amplification' of
>certain bass notes under certain conditions.
Additionally, the ear tends to "fill in" pitches that you think
should be there, whether they are or not. If you have one bass clarinet
playing low G, and a second bass clarinet playing D above that (and
they're perfectly in tune), you ear hears the pitches as the 2nd and
3rd partials of a lower tone - which happens to be an octave below the
lower pitch. Thus, you may "hear" a contrabass clarinet playing G an
octave below the lower bass clarinet, even if there isn't one there.
You can, however, tell the difference in sound between a real
contrabass clarinet, and an imagined one ;-)
Enjoy,
Grant
--
================================
Grant Green Contrabass.com
Sarrusophones & contrabass winds
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================================
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