Re: Lilypond help - arbitrary accidental glyphs

[Clive So]

Note that in E31, the rational interval 7/4 is on the augmented 6th, or 25 E31 tonesteps, whereas the minor 7th is on 26 E31 tonesteps, one E31 tonestep higher.

Yes, absolutely! Many people think of the interval 7/4 as a type of 7th (harmonic, barbershop, etc.) but I strongly believe that it should be understood as an augmented 6th (125/72 ≈ 7/4). Just because it's a 7-limit interval, it doesn't make it a 7th. Likewise, you don't call the JI major 3rd a "5th" because it's a 5-limit interval. This has important implications in terms of voice leading and harmonic progression.

Fokker (and hence the "Dutch school"?) happened to have chosen to use flats exclusively (semi-flat, flat, sesquiflat, double-flat, and even 2½ flat!) for practical reasons, but I don't agree with that as it obscures the harmonic function of each note. This has the consequence that the interval 7/4 is spelt, for example, as C - B-sesquiflat, making it look like a sort of 7th. Although the "Dutch school" approach doesn't have the same notion of harmonic function as in the traditional sense, Fokker did consider the interval 7/4 to be a sort of 7th, and consequently the chord C - E - G - B-sesquiflat a "dominant 7th". This is in direct contradiction with JI theory.