In October this year I am going to make a soundscape installation for the Nederlandse Muziekdagen, for the concert hall of the Muziekgebouw aan ’t IJ in Amsterdam. I am working together in this project with light artist Jaap van den Elzen, who is going to make a lightscape with the LED-walls in this hall. Las month Jaap and I went to see the amazing and endless lighting possibilities in the Muziekgebouw.

We were told that it will be the first time the light installation is used for such a light- and soundscape. Electric lutenist and improvisor Jozef van Wissem will be the living component in the installation. The mixed media work currently goes under the working title Waxing, Waning.

I wrote my first two Graduales in 2007, as Verwandlungsmusik between the different parts of the Missa Prolationum of Johannes Ockeghem (ca.1410/30-1497) - an example of strict canon writing from the Franco-Flemish school of the Renaissance .

The title Graduale refers to a missing Mass movement in Ockeghem's work – and to the minor-scale ( ‘Gradus’ meaning scale in Latin) on which both Graduales are built. They use the principle of change ringing: a maximum of combinations with a limited number of bells.

After hearing Graduale 1 & 2, Rotterdam Doelen programmer Neil Wallace asked for two new works in this series, which I finished in February. The four Graduales are going to be performed in the new Red Sound Festival, by VocaalLAB Nederland (who super-performed my 7 Interludes last year).

In Graduale 3 the same scale is used in a process in which the three top voices gradually draw closer to each other. Graduale 4 is a kind of procession that recalls the 7 Interludes – related vocal works that I wrote a year before.