“You can imagine that this is inspiring for someone who makes music,” says Tammo Jan Dijkema of the Radio Telescope Dwingeloo. Today, the historic radio telescope plays a special role in an international music project.
The piece will be performed during a concert in Freiburg, Germany Le noir de l’étoile by the French composer Gérard Grisey, with live signals from the Dwingeloo telescope.
The piece processes the rhythmic pulses of a so-called pulsar. “A pulsar is the remains of an exploded star,” Dijkema explains. “The star exploded and collapsed into a sphere about twenty kilometers in size. This caused it to spin extremely quickly.”
According to Dijkema, you can compare that process with a figure skater. “When a skater turns a pirouette, she starts with her arms wide. As soon as she pulls her arms in, she starts spinning faster and faster. The same happens with a pulsar, but it spins 100,000 times faster.”
The pulsar now rotates on its axis approximately once per second. “It emits radio radiation on one side, like a kind of lighthouse,” says Dijkema. “When you point the telescope at the radiation, you receive a radio signal in the dish with every revolution.”
The well-known French composer of modern percussion music Gérard Grisey composed a piece of music to the rhythm of a pulsar in 1991. That same year the piece was performed twice with a live signal from a pulsar, once via a telescope in France and once via a telescope in England. It has not been carried with a live signal since.
Students from the Hochschule für Musik in Freiburg are conducting research into this piece of music. “They will perform it again in a concert hall on November 14,” says Dijkema. “They want to do this again with a live signal from a pulsar. That’s why they asked us to transmit the signal to the concert hall in Freiburg.”
The pulsar gets a solo moment of three minutes. “Then two hundred people in the room listen to the rhythm of the pulsar. Then the percussion instruments take over that rhythm, and new music is created around it,” says Dijkema.