Oscilloscope Music - "Spirals" by Jerobeam Fenderson

After two months, I finally restored the main functions of the Tektronix Type 503 (replacing an arced transformer and the power circuit's capacitors). As such, I wanted to get back to testing oscilloscope music on the scope.
The music for this video is "Spirals" by Jerobeam Fenderson (2016), who used software to convert visuals to audio signals, which are fed to the scope's horizontal and vertical controls (in X-Y mode). Plainly, the visuals generated on the scope are the waveforms of the audio signal.
The artifacting on the trace is due to the low-frequency sampling rate limitation on the iPad (despite playing from the lossless FLAC format).