What happened before:

By chance, in the autumn of 2003, I saw a TV programme about the work of marine biologist Michel André, who anchors buoys equipped with underwater loudspeakers in the strait between Gran Canaria and Tenerife in order to warn and protect the cetaceans (whale-like mammals) from large ships with ultrasonic sounds. In recent years, some whales have been hit and killed by ferries during their resting period. After a meeting with Michel André, it became clear to me that without the scientific work of Dr. C. Kamminga (Technical University Delft – Netherlands, Research on dolphin sounds) such a work could not be realised.

Course of the project:

– Historical sound recordings

The analogue underwater sound recordings of Dr. C. Kamminga, which are stored at the TU Delft and in Amersfoort, are a sound source for the composition “Cetacea”. The sound recordings are recorded on a special tape recorder (Racal store 4d) at the speed of 60 ips. With this technique, sonar can even be registered up to 300,000 Hz. It would be conceivable to archive Dr. Kaminga’s most important recordings on CD during the work and also make them available to the dolphinarium in Duisburg, Germany.

– New sound recordings and the processing

Together with the scientist Avi Cohen Stuart (assistant of Dr. C. Kamminga) and the sound technician Bert van der Wolf I made new digital sound recordings of dolphins in the dolphinarium of Duisburg on 15.4.2004. The director of the dolphinarium is Manuel Hartmann, a student of C. Kamminga.

With the new digital technology (sample rate 384 Khz) very good quality sound recordings could be realised, which also allow a more versatile digital processing method.

The sound of the dolphins is ultrasound (-150,000 Hz), which is then transposed downwards into the audible frequency range (-20,000 Hz) and serves as sound material for the composition “Cetacea”. Of course, the transposition also changes the time constant. This is desirable, however, because the dolphins’ clicks are normally emitted in very short time intervals (clicktrains) and are not perceived by the human ear as rhythm patrons.

– Senegal

The compostion Cetacea was made in collaboration with Doudou N’Diaye Rose, the well-known Senegalese Sabar drummer.  The sabar is a single-headed, conical wooden drum covered with a goatskin and stretched with wooden stakes. “Sabar” refers not only to the drum, but also to the dances and festivals accompanied by these instruments. The sabar is played on religious and social occasions such as baptisms, weddings and other celebrations. Doudou N’Diaye Rose is in a caste of musicians called griot (Portuguese from criado = servant). He knows about the secret power of rhythms and their tonal languages (talking drums) and the history of his own tribe, preserved in epics, is transmitted from father to son. The drum language is the direct natural reproduction of the language in Senegal. It is like a script that everyone knows, only it is not read but heard. This language, the rhythms of Doudou N’Diaye Rose, are integrated live and/or as sound material into the composition “Cetacea”. In July 2005, I rehearsed parts of “Cetacea” with Doudou and his group in Dakar and received new musical inspiration for the composition.

About the electronic composition part of “Cetacea”

Because of the above-mentioned sound recordings and the processing technique, the basic material of “Cetacea” consists of rhythmic clicks in different pitches. In addition to this rhythm/sound carpet, noises such as moans, trills, squeaks, creaks and the familiar whistling of dolphins occur in “Cetacea” and are embedded in the composition in a signal-like manner. In addition, there is a low organ point (25 Hz – 150 Hz), which produces a bass register.

However, since the most important sound material for “Cetacea” consists of “sonar”, which travels 4.5 times faster in water than in air, but is relatively quiet and has shorter wavelengths, these premises also apply to “Cetacea” . The composition “Cetacea” therefore is relatively quiet, but very direct in terms of spatial acoustics. Since sonar is related to radar, “Cetacea” has a pulse-like “rhythm language”.

About “Cetacea”

There is thus a musical contrast between the fragile, quiet, electronic compositional part and the physically expressive, signal-like beats of the 6 percussionists. The percussionists play their own rhythms from Senegal and new composed rhythm patrons derived from the clicking structures of the dolphins. The electronic composition is 5-channel. Both the 5 loudspeakers and the 6 percussionists are distributed around the concert space. The loudspeakers can be installed between or opposite the percussionists. This spatial concept ensures that contrasts between the different rhythms of the dolphins and the percussionists are made clear, or that straight connections are created that can be perceived acoustically and musically.

About the performance of “Cetacea

In cooperation with the “Westdeutscher Rundfunk” in Cologne (Markus Heuger) and the world music festival “Traumzeit” (Wilfried Schaus-Sahm) “Cetacea” premiered on May 21st, 2006 in the Landschaftspark Duisburg-Nord in the foyer of the Gebläsehalle. On July 15th, 2006 “Cetacea” was broadcast on the German Radio WDR 3 “Studio Akustische Kunst” (23.05-00.00 h.).