High-end cassette decks had an "MPX Filter" which was a sharp 19kHz filter before the recording system.
And FM broadcasts have a high-frequency pre-emphasis, which adds something like 10dB of boost to audio high frequencies. This is to reduce high frequency noise that occurs in analog FM systems. Radio receivers have a matching de-emphasis high-frequency cut.
Indeed, both vinyl phonographs and audio tape systems employ similar pre-emphasis and de-emphasis. It's the RIAA curve for phonographs. Not sure what the standard is for mag tape.
Accidental DRM even before the "D" came to be.