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jdowning - 7-24-2015 at 11:14 AM
My pleasure!
For the 'ring sound hole' tests the circular discs will be mounted centrally in the sound hole on a thin, deep support glued on each side of the sound
hole. Fish glue will be used as it is fairly strong when dry but easily softened and weakened with water and heat - so the support beam may be easily
removed after the tests have been completed.
Each disc will be clamped to the support beam with a screw.
jdowning - 7-25-2015 at 11:05 AM
The support beam has been glued across the sound hole using water soluble fish glue that hopefully will be strong enough for the task in hand.
Clamping force for gluing is applied with a temporary flexible 'strong back - both strong back and support beam have reference marks to ensure central
positioning of the disc mounting screw in the sound hole.
Will leave the glue to cure overnight before starting trials.
It will not be necessary to remove the strings for the trials so measurements will be recorded with the sound board under full string tension (but
with strings damped with felt to prevent them from vibrating).
jdowning - 7-28-2015 at 11:31 AM
The 'ring' sound hole test has been completed with solid dics mounted centrally inside the colascione open sound hole of 7.6 cm diameter (D). Six
fibre discs with diameters ranging from 4.2 cm to 7.4 cm (d) were used the air resonance signal in each case recorded with a Zoom H2 digital recorder
positioned over the sound hole area. With strings damped air resonance was initiated by tapping the sound board just in front of the bridge. The
recorded signal in each case was then spectrum analysed with 'Audacity' to determine the resonance peak.
The attached normalised graph of frequency f/f0 (f0 =198 Hz open sound hole) and d/D now includes the meaured results.
The curve of the measured results is a bit closer to the curve obtained from resonance chamber tests than I might have expected.
However the calculated curve for the colascione has not been validated by this latest test so can be ignored.
Here the original assumption that the measured air resonance frequency of a circular sound hole with active area A is identical to that of a ring
sound hole of the same area with outside diameter D measuring 7.6 cm - is shown not to be valid.
jdowning - 8-11-2015 at 06:50 AM
The most recent paper from MIT about the evolution of air resonance power efficiency may go some way to explain why the calculated curve (red curve)
f/f0 against d/D is lower than the measured (green) curve in the graph previously posted. Refer to Figure S1 on the first page the Supplementary
Information here
http://rspa.royalsocietypublishing.org/content/royprsa/suppl/2015/0...
Although this compares air resonant frequency of narrow and long violin f shaped sound holes to circular sound holes with the same area and circular
sound holes with the same peripheral length the same basic consideration applies - area of round soundhole compared to a slender, long ring sound hole
of the same area. I must do the calculation for peripheral length for comparison.
I plan to undertake two more sound hole acoustic trials while the colascione is set up for air resonance testing.
The first will be with half ring sound holes - using the same central discs as before but with half the sound hole area blanked off with a thin metal
plate.
The second will be to test sound holes of 'half moon' configuration. The circular sound holes used for previous tests being reworked accordingly.
The additional quantitative data from these tests may help in further understanding of how sound hole shape influences the air resonance frequency.
jdowning - 9-1-2015 at 02:04 PM
The test for the 'C' type sound hole (i.e half ring sound hole) has been completed and a normalised plot of resonance frequencies f/f0 against d/D is
attached for information - very similar to the results for a ring type sound hole previously posted but with lower air resonance frequencies (smaller
area of sound hole).
For comparison with previous results, the spectrum analysis for a d/D of 0.7 is also attached - the point where with the central area of the sound
hole blocked the air resonance frequency has been reduced by less than a semitone.
Next to remove the temporary support in the sound hole in order to test a 'D' or 'half moon' sound hole configuration.
[file]36560[/file]
jdowning - 9-6-2015 at 02:22 PM
The temporary central sound hole bar has been removed (with water brushed on and a hot thin artists spatula) to measure the air resonance frequencies
for 'D' shaped sound holes of different diameters.
The results posted here for information have been computed for comparison with a round sound hole based upon sound hole area and sound hole periphery
(i.e. the length of the sound hole boundary or edge).
As the MIT tests have shown (verified by the more basic testing reported earlier in this thread), most of the air flow at resonance through a sound
hole occurs at the sound hole outer edge or periphery. So that a round sound hole is rather 'inefficient' with the majority of the inner part of the
sound hole (typically an area of 0.7 sound hole diameter that I call the 'dead zone') contributing little to the oscillating resonant air movement
across a sound hole.
From these results it can be seen that the sound hole geometry does have some effect but this is rather small when comparing a circular open sound
hole with a 'D' shaped semicircular (or non semicircular) sound hole of the same area or periphery.
No doubt this result will also be similar to a comparison between single round and oval sound holes (the latter found on some modern ouds) - i.e.not
much difference as far as air resonance frequency is concerned - all else air volume etc. being equal.
[file]36653[/file]
[file]36657[/file]
jdowning - 10-1-2015 at 11:54 AM
From the test results it has been decided to stick with the G1 G2 D3 tuning (octave and a fifth interval or the first three tones on the harmonic
series). This gives a powerful bass sound that I believe is primarily due to the air resonance effect - the sound board being quite small in surface
area (see attached image - my medium size hand pretty well covers the surface).
The sound hole will be left open for now just in case the neck requires resetting but eventually a parchment rosette will be fitted - as on the Dean
Castle and other surviving colascioni - the rosette, however, having no significant effect on the air resonant frequency.
Here is a brief audio clip to give some idea of the sound - the 'squeal' of the wound basses will require attention! - more to follow.
(Unfortunately the audio files are now lost)
jdowning - 10-1-2015 at 03:07 PM
The only known parody of Colascione music is written for a Chitarone (an Italian, extended neck, bass lute with up to 14 courses) by Girolamo
Kapsberger (Libro Quarto d'Intavolatura di ChitaroRoma 1640). Kapsberger provides the then alternative name for a Chitarone as a Tiorba (Italian
"Chitarone over Tiorba" - i.e. Chitarone otherwise known as a Tiorba).
The Chitarone was generally strung in gut (but sometimes with metal strings). There were typically 6 or 7 courses over the fretted fingerboard (single
or double) and 7 or 8 longer single contrabass courses leading to a second pegbox on the extended neck. The fingered courses measured from about 70 to
100 cm in length and were tuned like a Renaissance lute (in fourths with a third in the middle) except for the top two treble strings that were tuned
down an octave (due to the string length). The contrabass strings, 110 to 180 cm in length, were played open like a harp and were usually tuned
diatonically.
Athanasius Kircher in 1650 (mentioned on page 2 of this thread) tells us that the Tiorba was the invention of a Neapolitan street busker who took a
lute and doubled the length of its neck to make a baritone sounding instrument (with fewer courses than a lute) that was called - as a joke - a Tiorba
(pestle and mortar or hand grinding wheel). So this implies that this joke of a street instrument with its only 3 or 4 single courses (?) eventually
was developed to become the more sophisticated extended neck, double pegbox, Chitarone/Tiorba with its up to 14 courses.
As far as I can determine so far, in Italy any lute like instrument with a long neck, with single peg box and 3 or 4 single strings was called a
Colascione (or variants of that name). Therefore, some Colascione variants in Italy were also known as a Tiorba - an unsophisticated street instrument
- a long necked lute used as a bass accompaniment for voice or other instruments (or dance).
Attached for information is Kapsberger's manuscript composition 'Colascione' written in Italian tablature. In Italian tablature the six lines
represent the six strings of the lute that are stopped on the fingerboard and the numbers represent the stopped fret positions - 0 open string, 1
first fret, 2 second fret and so on. The bottom line is the top treble string (closest to the floor as seen by the player). The seventh course (open)
is represented by an O with a line through it written over the top line. In this composition only 7 of the 14 courses are employed. This composition
may be an elaboration of a simpler melody perceived by Kapsberger when he heard a 3 string colascione being played (possibly in duo with another
instrument?)
This interpretation of Kapsberger's composition for Tiorbo is by lute virtuoso Paul O'Dette (who has added a few notes not otherwise written in the
tablature)
https://www.youtube.com/watch?v=mhuwIBKkdPc
Although perhaps Kapsberger heard this combination of theorbo and bass colascione?
https://www.youtube.com/watch?v=7TJAh-cECB8&list=RD7TJAh-cECB8&a...
jdowning - 10-3-2015 at 03:33 PM
As noted in an earlier posting, historically, with all plain gut (or silk) strings the optimum tuning of a colascione of this string length (79cm)
might have been G2 G3 D4 (or G g d' or 98 196 294 Hertz). This represents the extreme practical range of plain gut strings with diameters of 1.04 mm
(2.8 Kg tension), 0.56 mm (3.2 Kg tension) and 0.4 mm (3.5 Kg tension) - A440 standard pitch.
For the current tuning an octave lower (G1 G2 D3), historically the G2 and D3 strings might be gut (or silk) but the octave lower bass string would
have to be a composite string of higher density (loaded gut or silk, or wound). Wound strings produce an amplified 'squeal' as the finger slides along
the string so an alternative smooth bass string may be the necessary alternative. As a first trial I will test one of my lead cored braided strings in
place of the Pyramid wound.
An interesting acoustic phenomenon of this style of colascione is not only the pronounced air resonance effect (in this case peak resonance at G3 or
198 Hz) but also the 'missing fundamental' phenomenon where the human ear in processing complex sound waves (ie a non pure (sinusoidal) sound
comprising a range of harmonics) detects a fundamental tone where none may exist (or is very weak in intensity) - although the overall tone 'colour'
may be different. In detecting the upper harmonics the ear is deceived into assuming the lower pitched fundamental exists.
Attached are previously posted 'Audacity' Fourier series spectrum analyses for comparison. To my ear the G1 bass is relatively strong (loud) yet
barely registers in the spectrum graph loudness scale (dB).
Attempting to play the colascione feels very strange at the moment for me as a lute player. Plenty of space around the player is necessary to avoid
problems with the long neck accidentally contacting neighbouring objects such as computer monitors or low ceilings etc.! A shoulder strap seems to be
essential for adequate control.
As a lute player I am using soft finger tips to pluck the strings that are quite widely spaced at the bridge but a pick, plectrum or risha would be an
historical alternative allowing an increased string tension.
One advantage of only having three symmetrically positioned strings is that the instrument may easily accommodate both right and left handed players
without any structural modification - just switch the strings over from bass to treble and vice versa.
For the 'long' string length (79 cm) and relatively 'low' string tension (in the 2.5 to 4 Kg lute range) tonal pitch can be significantly altered by
'bending' (stretching a string sideways on the fingerboard) also enabling pitch vibrato -good for vocal accompaniment (?). Under these circumstances
there seems to be little point in 'micro tonal' fretting the instrument other than basically 12 tone Equal Temperament (frets adjusted by ear for
acceptable intonation).
[file]37043[/file]
[file]37045[/file]
jdowning - 10-13-2015 at 09:39 AM
The G1 pitch Pyramid wound string has been replaced with the 63# 2 strand lead core prototype string left over from previous trials. Calculated
tension is about 2.5 Kg which should be about right.
http://www.mikeouds.com/messageboard/viewthread.php?tid=10010&p...
The string is only just about long enough to fit and will take a while to stabilse in tension no doubt. If this preliminary test is favourable I will
likely make another 2 strand core string using a finer weave braided jacket for maximum smoothness.
Comparative sound clips will be posted later.
(Note: the above link is to yet another topic of mine on this forum where image files, essential to understanding the text, have been lost for some
unknown reason. I do not have the lost images on file so cannot replace them - even if I had the time and energy to do so!)
jdowning - 10-27-2015 at 11:26 AM
The prototype braided G1 pitch drone string has been on the colascione for about 10 days and is still settling down - requiring tuning up slightly
each day - but otherwise not a problem. The thicker string also requires some adjustment to fret spacing in the higher positions to eliminate slight
pitch increases. Use of higher string tension might also help.
The first and second melody strings (tuned D3 and G) are Pyramid 0.63 PVF and 1010 wound. Note that the chosen historical pitch intervals of an octave
and a fifth are the first three tones of the harmonic series.
The two attached brief audio clips - recorded on a Zoom H2 digital recorder are raw and otherwise unenhanced.
The first is that of the open strings played in succession. I am using a stiff leather plectrum or mizrab as some of the Italian sources have
indicated that the Colascione plectra (or tacconi) were made of leather. I have not been able to confirm this independently but leather works OK.
The tonal difference between the braided and wound strings is obvious and as expected with the wound string having that typical metallic 'brassy'
sound rich in upper partials.
The second audio clip represents the Kapsberger 'Colascione' theme in order to evaluate string noise generated by left hand fingers sliding along the
string. Not as pronounced as on the wound string (previously posted) but still there nevertheless. A bit like the sound of sandpaper sliding on wood I
suppose.
On balance I think that the braided string has potential for this instrument so will make another string with smoother braided sleeve and hopefully a
tighter wound lead core. I also plan to replace the #1010 wound string with a braided lead core string just to see how that works out.
(Unfortunately the two audio files have now been lost!)
(Also, due to a family tragedy, all further work on this project has been postponed until further notice).
jdowning - 3-17-2023 at 08:49 AM
After an extended period confined to hospital and current rehabilitation process, I have been 'out of circulation' for the best part of two years.
Checking out Mike's forum again I note that this topic is missing all but one of many images essential for understanding the posted arguments and
comments. I assume that the loss is due to some kind of irreversible computer glitch (?) so thought that it might be a useful exercise, having located
my folder of images related to this topic, to try to reinstate at least some of the more critical images. This might also help in my rehabilitation by
exercising the mind!
I forget how to post images but will give it a shot as time and enthusiasm permits. If it doesn't work then 'c'est la vie' - time to move on!
jdowning - 3-17-2023 at 11:11 AM
About a year after my final post on this topic in 2015, following further research on the origins of the Colascione folk instrument, this article was
published in FoMRHI where I cast some doubt on the provenance of the instrument in the Dean Castle collection, Scotland with a suspicion that it may
originally have been a small treble lute (or lute related instrument) modified, with a new longer neck, to look like an Italian Colascione (or
Calascione).
https://www.fomrhi.org/vanilla/fomrhi/uploads/bulletins/Fomrhi-136/C... (FoMRHI Comm 2027)
This thesis, if correct, does not, however, affect the substance of this topic that is primarily concerned with the fabrication of a long necked lute
with metal bowl and consequent experiments to predict and confirm, by measurement, the air resonance of the body.
First attempts to re-post images on page 1 of this topic were successful - so, all systems go!
narciso - 3-18-2023 at 08:00 AM
jdowning, I greatly missed your wonderful posts to this forum while you were out of circulation. Looking forward to your taking up the reins once more
here on this thread about the Colascione, and elsewhere on the forum
I've also noticed btw that uploaded images generally seem to disappear from the forum after a while. My guess is it is just a cleanup setting on the
backend, not a glitch as such..
jdowning - 3-19-2023 at 07:32 AM
I don't understand why the image files disappear either. Some time ago Mike did say that it was not a purge so I took that to mean it was not
intentional and perhaps just a random event? I have started re-loading missing images at the beginning of the topic first using the image hosting site
Imgur that I have used successfully in the past and is in accordance with Mike's instruction for posting images on the forum. I thought that I might
try the alternative hosting site TinyPic this morning, for my education, but ran into problems trying to load the images. I was, however, able to load
the image files as thumbnails that expand in size for viewing by clicking on each file - an arrangement that I prefer.
If this is not the way to go for whatever reason perhaps I could be advised accordingly by Admin. before spending time on re-posting the images?
I have followed up on details of the FoMRHI Comm. previously posted about the Dean Castle Colascione and note that the soundhole rosette pattern is
similar but not identical to the rosette on the weird looking lute #1037 in the Stearn's collection of instruments attributed to notorious 19th C
dealer/ forger Leopoldo Franciolini. See here for link to University of Michigan, School of Music, Theatre & Dance - Fantastic Forgeries - scroll
down page to lute #1037,
//smtd.umich.edu/research-collections/stearns-collection-of-musical-instruments/search-the-stearns-collection/?gallery=Fantastic%20Forgeries
cdroms - 3-20-2023 at 11:02 AM
What an interesting and bizarre instrument! Following with interest, enjoying seeing the pictures come back up.
jdowning - 3-22-2023 at 09:21 AM
A bit more information about the colascione and related instruments is covered in the following articles (comms) in FoMRHI
https://www.fomrhi.org/vanilla/fomrhi/uploads/bulletins/Fomrhi-130/C... (FoMRHI Comm2027)
https://www.fomrhi.org/vanilla/fomrhi/uploads/bulletins/Fomrhi-131/C... (FoMRHI Comm 2037)
https://www.fomrhi.org/uploads/bulletins/Fomrhi-133/Comm%202042.pdf (FoMRHI Comm 2042)
https://www.fomrhi.org/uploads/bulletins/Fomrhi-136/Comm%202062.pdf (FoMRHI Comm 2062)
jdowning - 3-25-2023 at 06:21 AM
For information, I am now using TinyPic for re-loading the images. I have chosen image sizes of either 640x480 or 320x240 to avoid thumbnails but
providing images large enough to be clear should printed pages be required.
Note that I am also making changes/corrections to the original text, as appropriate, as I work through the topic.
jdowning - 7-29-2023 at 02:37 PM
So, once again, all of the missing images that I had taken time and trouble to repost earlier this year have been removed with no explanation from
Admin!!!
Something that needs fixing on this forum?
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