9.12 Musical examples

Filtering is not merely a technical tool. It is a core expressive device across a century of music.

Alvin Lucier - I Am Sitting in a Room (1969)

The quintessential demonstration of filtering, feedback, and room acoustics. Lucier recorded himself speaking, then played the recording back into the room and re-recorded it, repeating the cycle dozens of times. Each pass convolves the sound with the room’s impulse response once more, so the frequencies the room emphasizes grow louder with every iteration while the rest fade away, until the intelligible speech dissolves into the pure resonant tones of the room itself. It is the convolution reverb of this chapter applied over and over.

Daft Punk - Voyager (2001)

A showcase of subtractive synthesis in popular music. Nearly every part leans on filtering: gentle filters with moving cutoffs add motion to the pads, and a resonant low-pass sweep gives the bassline its vocal, funky “wah”.