The Toronto PET Users Group (TPUG) recently featured an interview with Stefan Powell at World of Commodore 2024. In this session, Powell explores Commodore 64 beat frequencies using simple one-screen BASIC programs and the SID chip’s unique sound quirks.
To enjoy the full experience, TPUG recommends wearing headphones. Powell begins with the external input of the 6581 SID chip. While often ignored or grounded, he embraces the noise as part of his compositions. By raising volume and adjusting registers with POKE commands, he transforms the raw input into the base of his beat frequency experiments.
Powell describes his first experiments as a child. He would spend hours writing programs that generated oscillating drones. These sounds became his personal background music, running for hours while he relaxed or slept. Years later, he returned to the C64 and rediscovered that connection. Since then, he has performed both privately and at live events.
During the presentation, Powell demonstrates how altering frequency bytes shifts harmonics. This creates evolving soundscapes that change slowly over time. He explains that the listening environment plays a major role. Speakers, room acoustics, and even RF interference affect the sound in unexpected ways.
He compares these explorations with minimalist composers such as Éliane Radigue, stressing how deep listening changes the perception of sound. To encourage experimentation, Powell shares short BASIC listings. Many rely on nested FOR loops or timing functions. According to him, these programs only show their true character on original hardware. Emulators fail to capture the noise and subtle imperfections of the SID chip.
This interview highlights how the Commodore 64 continues to inspire creativity. Powell’s work with Commodore 64 beat frequencies shows that the system is more than a platform for games. With only a few lines of code, it becomes a powerful instrument for exploring sound.
Watch the full TPUG video to experience these hypnotic SID tones and discover how minimal programs can create unique sonic textures.
