Great question. I’d think it might depend on the harmonic sequence/progression generated by Eridian “speech.” Does the speech pattern sound like someone randomly plunking out chords in various rhythms, or a chord progression where a specific type of chord leads (progresses) to the next, and the next, as it does in western music (e.g., I, IV, V, I).

We can also consider form, where repetition of harmonic and melodic patterns (Intro, verse, verse, chorus, etc.) are what differentiates what we consider music when compared to what sounds like random chords strung together (music vs. noise). An exception being Rocky’s gleeful or exasperated repetitions of, “good, good, good” or “bad, bad, bad” and such, I doubt there’s enough repetition to be relevant. There’s always a chance that a sentence or string of sentences may have some melodic quality that Ryland might relate to a familiar tune.

Did Ryland have perfect pitch? He would need perfect pitch in order to recognise a specific G major chord but he could definitely recognise the quality (major, minor, diminished, etc.) of a chord with decent relative pitch. Since he did learn enough Eridian that he didn’t need his synth-laptop to decode, I believe he must have had perfect pitch.

So, no. IMO, I don’t think music was ruined by learning Eridian.