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Wednesday, April 17, 2019

Yorgos Kertsopoulos performs using his innovation guitar support -amplifier version: "Superior" and two passive guitar's acoustical Timbre-Tone Equalizing Amplifiers "small" version, all attached on the double course guitar amplifying and equalizing the sound. Measurements have been taken and graphs are presented of SPL (db-dbA) meter, first measuring the room's threshold environment with no sound whatsoever (ambient sound) at 33db. Then, measurement of the guitar's sound one meter away from the SPL meter, without the amplifiers-equalizers giving an average reading of 70 dbA and measurement of the guitar's sound one meter away from the SPL meter, with the amplifiers-equalizers giving an average reading of 80 dbA. This 10 dbA average difference in the readings is perceived by the human perception as doubling of the volume (loudness). In SPL (Sound Pressure Level) criteria this difference of 10 dbA, between 70 dbA and 80 dbA is an increase of ten times more when the reading is 80 dbA in contrast to the 70 dbA. The innovation support-amplifier and equalizers are strictly pathetic acoustical members enhancing in an acoustical manner the sound of the guitar. They are not connected in any way to electrically or electronically working devices of any sort. As musical instruments, intonation is achieved to them, at all acoustical frequencies, they become an extension of the acoustical chamber-body resonator of the instrument itself upgrading the sound of any classical-flamenco or steel string acoustic guitar. An excerpt from his composition "magnapeiron" is performed in room conditions by Yorgos Kertsopoulos.The video of playing is taken by Apostolakis Konstantinos in room conditions at a distance of 1.7 m from the source and the recording has been left as recorded, no effect or mastering has been done on the sound. It is given here as recorded from the ZOOM Q8, as raw wave sound at 44.1 Khz.,,,,

Sunday, September 3, 2017

The Physics of the Guitar

Yorgos Kertsopoulos at the press conference in MUSIKMESSE Feb. 1983 presenting his "Mathematical Model and Geometric Progression of the Guitar" as "Physics of the Guitar".

The mathematical model of the guitar in detail
Kertsopoulos Aesthetics official site

Wednesday, August 15, 2012

Delos Instrument Series – The Guitar by Delos

However, the idea of diversity within the instrument is truly driven home by Smaro Gregoriadou’s album “reinventing guitar!“. In this recording, Gregoriadou uses three guitars created by inventor Yorgos Kerstopoulos: a triple-double-sing course guitar in re-entrant tuning, a single-stringed guitar in ordinary or low tunings with right-hand pedal, and a single-stringed high-tuned guitar with right-hand/movable back pedals and scalloped fingerboard. As Gregoriadou explains it, the “ Kertsopoulos Æsthetics consist of continuous retrospective research on the guitar’s history and traditions that belong in the vanguard of scientific, technological and artist advances in the world of classical guitar today It involves a series of pioneering achievements in the fields of guitar and string construction, aiming: (a)to connect the contemporary guitarist with the obsolete historical forms of guitar, and (b) to expand the modern guitar’s technical limits, offering potential solutions of its undesirable complexities, namely low volume, imbalance in the transmission from the 3rd to 4th string, dullness of trebles, and poor quality of tone.”

Reinventing Guitar
Smaro Gregoriadou

For reading the article please click on the title above

SMARO GREGORIADOU - Reinventing Guitar II - Smaro Gregoriadou (Guitars) - 013491341927 - Released: June 2012 - Delos DE3419

...In my review of guitarist Smaro Gregoriadou's first CD titled Reinventing Guitar reviewed on this page, I may have given the impression that the sound quality of the various instruments at her disposal was the key factor which made that recording so enjoyable. True, the wonderful instruments built by guitar-maker Yorgos Kertsopoulos, played on her first CD and again on her new recording Reinventing Guitar II, certainly deserve praise, but in the end, it's Gregoriadou's amazing musicianship that brings these guitars to life...

For reading the review please click the link on the title:

Thursday, February 16, 2012

Thank you to all European and Global friends for your support to Greece

A great thank you from our hearts to all our European and Global friends for your support and solidarity in these difficult moments for the Greek people. Greece loves you all, Yorgos

Wednesday, September 14, 2011

The Golden Ratio And The Guitar, A Match Made In Equal Temperament-Guitar International

By: Yorgos Kertsopoulos
In this article: Golden section and golden rectangles, the harmonic series and the model of its ideal behavior simplified, equal temperament and just intonation and a description of the beat frequency conflict produced by the deviations between simultaneous sounding of harmonic partials and prime frequencies and how it affects the tone and timbre of the guitar. Read to the end for some cool videos demonstrating the properties detailed here.
For reading the article please click here:

Sunday, January 16, 2011

The Kertsopoulos Pneumatic Foot Pedal Guitar-Gregg's Blogg

Below is an excerpt as written on Gregg's Blogg:
Alas, not a harp guitar as I had inferred, but still an amazing invention that opens up an entire new world (at least to me!). In a nutshell, all the extra strings and bridges and bars and levers and pneumatic gauges are for the purpose of applying the pedal effects of the piano to the guitar. At least that’s what I think! I’d love to hear what Al Carruth makes of all this cleverness.

This story started with a blog about a week ago, when the instrument was spotted (by Tom Shinness) on the Facebook page of Smaro Gregoriadou. The builder – Yorgos Kertsopoulos – somehow spotted it immediately and has written me a nice series of emails. He can explain it much better than I (I still have to see it work to understand it!).

His site and links to his many photos and articles are exhausting (now I know how my own site affects people!) – but I sense that they’ll appeal to many of you in the harp guitar community.

Have fun, and if you figure it out, let me know!

To read more on Gregg's Blogg please click here...

Kertsopoulos Aesthetics: The How and the Why – Part 3 - Guitar International

“The Kertsopoulos mathematical model and geometrical progression of the classical guitar, presented for the first time in such a detail.” Vol. 1 of 7.

For reading the article please click here...

Smaro Gregoriadou: Reinventing Guitar-Guitar International

Guitar International recently sat down with Smaro Gregoriadou to talk about her latest album, the instruments she’s playing on the record and get her thoughts on the modern, classical guitar scene...

Guitar International

For reading the article please click here...

Thursday, December 2, 2010

Another recent review on "Kertsopoulos" guitars

..."What I found remarkable about the new instruments is the way they allow for a much more detailed separation of the treble and bass voices, of the different musical lines within each piece. One guitar almost sounds like two separate instruments! "... CLASSICAL MUSIC SENTINEL of Canada, July 2010

Thursday, September 30, 2010

“Kertsopoulos Aesthetics” The How and the Why Part 2: The “Kertsopoulos High-Tuned Strings”-Guitar International

On Sep. 28, 2010 my second article was published at Guitar International Macgazine. Many thanks to the publisher Rick Landers, Head Editor Dr. Matt Warnock and the whole editing team for the wonderful presentation and their interest in my work.

For reading the article please click here

Wednesday, September 8, 2010

“Kertsopoulos Aesthetics” the how and the why – Part 1: Introduction - published by Guitar International

Many thanks to the publisher of Guitar International Mr. Rick Landers, Dr. Matt Warnock - head editor and the editing team of the magazine for their interest in my work. It is a great honor for me to write a series of articles concerning prototype details of my work at the respected magazine.
“Kertsopoulos Aesthetics” the how and the why – Part 1: Introduction, Everyone in his or her own way contributes to the guitar’s evolution, is my first article published today Sep. 8, 2010 at GI and I hope you enjoy it.

For reading the article please click here

Thursday, July 15, 2010

Recent review on "Kertsopoulos" guitars

...wonderful instruments built by guitar-maker Yorgos Kertsopoulos

...amazing instrument, a triple-double-single course guitar in re-entrant tuning.

Jean-Yves Duperron
Classical Music Sentinel

Read more on this review of "reinventing guitar" CD of Smaro Gregoriadou, playing with "Kertsopoulos" guitars and strings...

Tuesday, April 6, 2010

Excerpts from "A Little About Kertsopoulos Æsthetics For Guitar "- by Contrapuntist

…Throughout the history of the guitar, the number of strings has ranged from 4 to 6 courses. A course is a pair of two strings that were tuned in unison or octave. The baroque guitar had five courses. It wasn’t until the 18th and 19th centuries when the classical guitar began to resemble the modern classical guitar of today which uses six single strings. As a result, much of the guitar’s early repertoire is transcribed and arranged to fit within the current framework and “technical limits” of today’s guitars…

…I am going to tap into my personal experience as a classical guitarist for a moment. The classical guitar uses a combination of nylon and metal strings. Nylon is used for the top three with metal-wound strings used for the bottom three. As a whole, the volume the majority of guitars can project is much lower compared to other string instruments. When I performed with a violinist, my range in volume had to remain on the “louder” side. In many cases, I had to push the instrument to its limits hoping not to pop a string or pluck in a bad manner…

…The research conducted by George Kertsopoulos has simply tried to combine today’s guitar making techniques, improve upon them, and construct a series of instruments that give guitarists options to interpret older music accordingly. Classical musicians constantly debate about how older music should be performed. Should performance of music written in the 16th century sound like we are in the 16th century? Or, should musicians adapt to contemporary instruments and “modernize” interpretations of the music? This is an ongoing debate that will likely never come to end…

For reading the full article by Contrapuntist please click below:
by Contrapuntist on March 23, 2010
in Performance and Inspiration

Excerpts from "Album Review – Reinventing Guitar, Performed by Smaro Gregoriadou" - by Contrapuntist

...Reinventing Guitar is a festival for the ears that explores the different acoustic possibilities offered by Kertsopoulos Æsthetic guitars. The various guitars allowed Gregoriadou to interpret early music more authentically and offered a glimpse into the future acoustic possibilities of the guitar. After listening to other classical guitar CDs in my collection, it does sound as if the three guitars used throughout the album resonate louder than standard classical guitars...

...The acoustic range and characteristics of the guitars offer performers the opportunity to make unique interpretive choices for any given composition.

...All in all, Reinventing Guitar is a grand achievement.

Please click below for reading full review by Contrapuntist:
by Contrapuntist on March 30, 2010
in Classical Music, Sonic Perspectives

Friday, March 5, 2010

The greeting speech of Mrs.Amalia Ramirez at “forms & strings” – 7 Feb. 2009

Good evening.

My niece Cristina and I, came to represent and honor the memory of my father Jose Ramirez III, where 26 years have passed from his acquaintance with mr. Kertsopoulos at the exhibition of Frankfurt, where he presented the “mathematical model of the guitar”.

At that time I did not work in the family enterprise. Few years’ back, I had left the workshop and for roughly five years, I had not returned. However, I remember my father, who spoke to me with a lot of respect and admiration for the work of mr. Kertsopoulos, for his scientific prestige and seriousness and for his lovable, warm and hospitable character.

Now, I have the opportunity to experience personally these charismas that my father so much appreciated in mr. Kertsopoulos and his work. And it is for my niece and myself a pleasure and an honor to have been invited to participate in this event, which has a particular recognition and place in the world of the guitar.

We thank you for inviting us, as representatives of the Ramirez House, to participate in this event, to support and express our admiration towards the work of this outstanding guitar luthier, whose ability of his hands, is expressed through the perfection of his art on the instruments he constructs.

Thank you.

For a video of Mrs. Ramirez's speech please see below on this blog

For Ramirez guitars please see:

Thursday, March 4, 2010


On Feb. 7, 2009, the Museum of Greek Popular Instruments “Foivos Anogianakis” Research Centre for Ethnomusicology, presented at the Museum Benaki in Athens, a tribute to the history and tradition of the classical guitar, “forms & strings”: "Honorary tribute to Amalia Ramirez and the tradition of her family", with honored guests: Amalia and Cristina Ramirez. A guitar recital was presented and the guitarists played six different historical types of instruments as they are revived by the modern constructional methods of “Kertsopoulos Aesthetics”, soloists: Yorgos Kertsopoulos and Smaro Gregoriadou – "reinventing guitar"!

After the event Amalia Ramirez was interviewed by Dionysia Blazaki and commented on “Kertsopoulos Aesthetics”, Y.Kertsopoulos and the interpretational capabilities of the instruments heard and also the interpretation of S.Gregoriadou, “reinventing guitar"!

Below is the full text of the interview:

Dionysia Blazaki: Mrs. Ramirez, today you had a live experience of this particular proposition named: “Kertsopoulos Aesthetics”. What is the opinion you concluded for the musical result and how would you comment on the interpretational involvement, which Smaro Gregoriadou gives through these “aesthetics”?

Amalia Ramirez: I am very surprised, dazzled, because what I managed to observe is that every instrument has a very different personality.
It is as though every instrument constitutes a different path of expression.
They are very different from the usual guitars of the rest of the world.
Maybe there is one guitar, the first played by Smaro, which resembles the usual known guitar.
These guitars possess antique sounds, sounds with an ancient charm.
I believe Smaro is very talented and plays with a lot of sentiment. She is clear, Clear…

D. Blazaki: Thank you…would you like to say something else?

A. Ramirez: I would continue to comment…Yes; I would like to say some things more.
I think that Yorgos is a genius. All these are a miracle. He is a revolutionist; he is extremely original, extremely authentic. I was thinking as I was listening, something my father used to say when he met something exceptional.
He was saying: “when you see someone in a parade to march with a different step, this happens because he hears other drums playing”…drums…other drums.
He is not part of the mass.

D.Blazaki: Thank you so much.

All of us thank you from heart Amalia, for giving us the honor and the happiness to present an “honorary tribute to you and the tradition of your family” with you and Cristina being with us and I also thank you from heart, for your kind and very important comments, concerning my work. We wish you and all your family and staff happiness and to keep us always inspired with your wonderful, superior and fascinating instruments.

For a video of the interview please see below on this blog.

Thursday, October 29, 2009

Welcome to "Kertsopoulos Aesthetics" methodology: Guitars & Strings

Welcome to "KERTSOPOULOS AESTHETICS", the revival of the different forms, tunings and sound timbres the guitar possessed in its history.Yorgos Kertsopoulos is a soloist in classical and flamenco guitar and author of "Space-Time Theory Vol. A' The Philosophy of Space-Time".Composer and professor of the guitar, he specializes in invention and construction of guitars, strings, loudspeakers, microphones, equalizers, mixers and amplifying systems. A researcher and inventor of theoretic models based on scientific applications has found international acclaim on his publishing (DAS MUSIKINSTRUMENT--Frankfurt 1983, Heft 9/ September 1984, in German and English-"The Physics of the Guitar") and international presentation of "the Guitar's mathematic model and Geometric progression" (1983, International Music Messe-Frankfurt, College of Furniture-London and seminars to respected luthiers and guitarists of England invited by GUITAR magazine of George Clinton...from now on after this presentation and know-how given by mr. Kertsopoulos, better guitars will be constructed throughout the world. I can personally assure you of this fact because now we have no more secrets in construction. His work is so unique in its scientific approach but also so full of traditional truths, it includes everything...Jose Ramirez (at the press conference given by Y.Kertsopoulos at the Music Messe in Frankfurt-1983). In 1972 won the first prize at the International Guitar Competition of Milan and in 1975 obtained his soloist diploma in guitar (First prize, National Conservatory of Athens under Dimitri Fampas). He has given concerts in Europe, U.S.A. and Canada and played with orchestras (New York chamber orchestra-U.S.A. 1978) at the time he lived in Canada and was professor of guitar at two universities (Concordia-Montreal 1976-81, State University of New York-Plattsburg 1978-81). In 1994, he presented his "pedal guitars" where each one out of ten different constructions depending on the constructional design gave in their own specific manner enhancement to the guitar's sound in a similar manner the pedals of the piano do for the pianist. Also, in 1994 he presented the "Kertsopoulos Aesthetics", involving hundreds of different guitar "aesthetic" sounds which can be produced from a guitar varying accordingly in timbre, volume, character and tuning pitch. This is achieved through his invention and construction of strings made of new to the guitar acoustic materials. His metallonylon and metallonymatic trebles for Baroque-Renaissance or modern music are a reality in the guitar world and many guitarists play with these for their unique timbre, sonority, volume and special interpretational capabilities. All tunings are now possible from --5 to the 12th fret with the "Kertsopoulos Aesthetics" with especially designed strings of numerous combinations in color and timbre for each tuning chosen. (Excerpt from the CD entitled "Kertsopoulos Aesthetics" Produced by Plinthos 99).
Smaro Gregoriadou, an internationally acclaimed soloist guitarist, composer is the official international artistic representative in concerts and recordings of the "Kertsopoulos Aesthetics". Many internationally acclaimed guitarists-professors have studied and obtained their diplomas under the teaching of Y.Kertsopoulos among them: S.Gregoriadou, D.Blazaki, M.Spanggaard, P.Deligiannis, A.Mazi, K.Stavridis, E.Kapetanaki, E.Theofanous, E.Sfikas, K.Zarkadoulas, M.Bafounis, M.Sakellaraki, N.Kakavelakis...
...Being a holder of different discoveries in the theoretic and practical constructional field of the guitar and acoustics in general, Y.Kertsopoulos constructs instruments of an unmatched (by today's standards) acoustic performance in quality and sustain, in concert hall conditions (DAS MUSIKINSTRUMENT-Frankfurt 1983, Heft9/September 1984).
The great master Jose Ramirez wrote the following dedication letter to Y.Kertsopoulos for his work on the "Mathematic model and geometric progression of the guitar-The Physics of the Guitar":
"The work realized by mr. Kertsopoulos on the mathematical configurations of the guitar's outline deserves all my respect and admiration not only from its scientific approach but also from the fact that it is a serious study enlightening all these delicate details found on the form of the instrument not defined sufficiently by tradition. With my regards, signed Jose Ramirez, April, 8, 1983".
Highly recommended: Newly released CD, reinventing guitar! by Smaro Gregoriadou (July 2009) by DELOS music. For more info. please view:
Space-Time Theory Vol. A' The philosophy of space-time by:Georgios K. Kertsopoulos has been published by: SYNCHRONI EKDOTIKI and was presented at the FRANKFURTER BUCHMESSE 14-18 Oct. 2009. Yorgos was present at the fair and gave a press conference on Fri. 16, 15:30-16:30 at room EXPOSE, Halle 3.C, Eastern.For more info: please see:

Kertsopoulos Aesthetics on youtube: