(Following a Stradivari trail by Amara Graps.)

Input Data.

The original sound files are from a Nigel Kennedy 1992 CD performing live the Beethoven Violin Concerto in D Op. 61 with the Sinfonie-Orchester des NDR conducted by Klaus Tennstedt. On two separate nights, as an encore, Kennedy performed two different J.S. Bach pieces. My working assumption is that Kennedy was playing a special Stradivarius violin called "The Cathedrale". (In the middle 1990s Kennedy bought "The Cathedrale" that he had been borrowing up to that time, and then immediately traded it for an even more special Guarneri violin: "The Lafont".)

I selected a sixty seconds sample from the middle of each. Then I mixed the two stereo channels for each Bach piece into one monochannel, and saved each as an ascii file. I selected 50,000 consecutive points (=2sec) at ten different places in each one million point (= 60sec) ascii file.

Preludio	Allegro

Preludio means music from J.S. Bach: Preludio from Partita No. 3 in E

Allegro means music from J.S. Bach: Allegro assi from Sonata No. 3 in C.

Frequency Transformation.

I converted those ten different data-extractions from each sample into frequency space using a wavelet Daubechies 18 filter and a discrete wavelet transform from Wavelet Workbench.

The lowest frequencies are at the top scales of this two-dimensional plot, and the highest frequencies are located in the bottom scales. One key to answering this question then is: Where is the "activity" located for each violin ??

Preludio	Allegro
Preludio	Allegro
Preludio	Allegro
Preludio	Allegro
Preludio	Allegro
Preludio	Allegro
Preludio	Allegro
Preludio	Allegro
Preludio	Allegro
Preludio	Allegro

Home	Last Modified by Amara Graps on 1 September 2002. © Copyright Amara Graps, 2002.