I can see how that makes sense for a publisher, but for a homebrew game? It’s a lot of work, and it wouldn’t be worth it if it were just duplicating another game.
Funny, but that "duplicating another game" was exactly how the OSR was born... (see also
OSRIC, and
Dark Dungeons)
This is a fairly good read. I would boil it down to music theory and music artistry. A piano and guitar are different, but do work on the same tuning, notes, and playstyle. You can write sheet music that works for them both. That would be the mechanics side of RPG design and theory discussion. The actual creation, writing, and performance is the aesthetic piece that's more subjective. This would be the adventure design, role play, etc... of RPG theory.
That's not a terribly apt comparison - the differences in mechanics make sheet music playable on both without abstractions (in other words, no cheating by Figured Bass or Chord Symbols, instead writing each note) make the overlap a technical challenge without much room for art. The mechanics of each instrument have wide ranges, but the overlaps make life bloody hard on the composer trying it...
The instrument is really the comparative to the game mechanics - covering what can and cannot be done.
Given that both instruments are tunable, the tuning chosen is comparable to the playstyle.
The Music Theory is not quite, but almost, universal - functional harmony is the same in the Chinese, Japanese, Middle Eastern, and European contexts, and are built upon ratios of frequencies.¹
Interval Name | P1 | min3 | Maj3 | P4 | P5 | P8 |
Ideal Ratio | 1:1 | 6:5 | 5:4 | 4:3 | 3:2 | 2:1 |
Those key frequency pairings are fundamental to all musical cultures, tho' often specific instruments and/or tunings intentionally deviate in small ways. It can be said that Shönberg and Weburn are non-funtional - they specifically try to avoid the functional interval changes.
ANd that's the point where the analogy presented goes careening off the bridge.
Music Theory has strong mathematical basis for why what sounds good does so. Games have no comparable universal.
Modern Music Theory classes are, at least for the lower division sections, typically, "how to emulate Bach, then Beethoven, then Mozart." It would basically be, "Retrocloning 100-104." (Exams being, quite literally, "apply [Bach/Beethoven/Mozart]'s formulae and fill in the missing notes." It's not interesting until upper division. Even then, a lot of it is still emulating other's styles.
¹
Musical Scales and Intervals