When Dmitry Morozov was offered a pyrite disc in the US, it was given free of charge on condition that the Russian media artist, circuit bender and musician create something sonic with it. He came up with a combination of optical media reader and digital music instrument called Ra, which uses a laser to scan the uneven surface of the pyrite sun and produce synthesized sounds.
Pyrite is a pretty common mineral around the globe, its brassy color giving it more than a passing resemblance to gold. There are a good few forms and varieties, but the pyrite suns or pyrite dollars – roughly disc-shaped formations with striations bursting out from the center – are found only in Randolph County, Illinois.
Morozov was gifted one of these discs by a mineral seller in Boulder City on the condition that he created something with it. Inspired by articles on using lasers for the preservation of sounds from audio recording mediums of yesteryear, Morozov began working on his own laser scanner that would transform the surface irregularities on the pyrite disc into synthesized sounds. The project was further spurred on by a commission from the Sound Museum in St Petersburg, Russia, and led to the creation of Ra.
The mains-powered device uses a Raspberry Pi and Arduino Nano as its brains, and features a digital sound processor, stepper and servo motors, a 3 V mono sound system and a custom laser pickup/reader. A control board runs down one edge of the triangular base, with nine switches and 10 knobs for dialing in envelope filters and modulations, setting processor parameters and choosing from 16 DSP effects programs.
The speed of the spin, the disc's direction, and the position of the custom laser pickup/reader can also be set by the user. Morozov has included a built-in speaker that towers above one side of the control panel, but there's a line out jack too.
You can see and hear what sonic secrets the pyrite sun has to reveal in the video below.
Source: Dmitry Morozov