In his excellent Practical Typography, Matthew Butterick writes in the chapter “Grids”:

Fans of mathematical ratios in grids (also known as modular scales) sometimes compare them to music. For instance, Robert Bringhurst says “a modular scale, like a musical scale, is a prearranged set of harmonious proportions”. (The Elements of Typographic Style, p. 166.)

As a musician, I find this metaphor incomplete. Sure, music is written on a grid of harmony and rhythm. But performers don’t rigidly adhere to these grids. Indeed, music that was locked perfectly to a grid would sound sterile and boring. Just as the performer’s ear is the ultimate judge of the music, the typographer’s eye is the ultimate judge of the page.

I actually agree with much of Butterick’s point here (indeed: if the only thing that comes of my writing this piece is that you go read and learn from Practical Typography, I will consider this a win). However, his comment about musical grids gets a couple things quite wrong in my view as a composer of music — and the ways it goes wrong are themselves illuminating:

1. The performer’s ear is not the ultimate judge of music — at least, not of all kinds of music. Butterick may be thinking here of styles heavier on improvisation and alteration: styles I like and play a fair bit myself, but not all styles. As a composer, I would find it quite offensive if a performer decided to ignore the melodic and harmonic “grids” I chose. So would most audiences for “classical” music (whenever it was composed), where the composers’ intent is highly prioritized.

2. That being said, the composer’s ear is in most cases the ultimate judge. Sometimes the right harmony for a given moment in a piece is not the “normal” one for the scale and progression; indeed, sometimes the surprise of doing something a little bit weird is the point. You can only tell that something is a “little bit weird” if there is a coherent baseline to refer to, though!

3. The exceptions to the second point are in the context of other compositional choices, e.g. to use a tone row, or more generally to stay strictly within a given tonal structure — from constructed tonal systems in modern music¹ to the strict counterpoint works of historical masters like Palestrina and de Victoria. To reiterate, though, this is still a conscious choice.

4. Finally, even in highly-structured composed music, there is considerable freedom to the performer (including a conductor): How are tempo and dynamics to be interpreted? Just how much emphasis does a marcato imply? How tightly or loosely should this follow the rhythmic markings here to convey the musical sense of the section?

With those points in mind, I offer an alternative formulation of the same closing paragraph:

An addendum: It is true that advanced composers or performers can go far away from harmonic scales and metrical grids to accomplish their musical ends. But it is also true that beginning composers do not start that way. The course of study begins with very rigorous structure, most often following the course of musical history. Formal instruction in composition, for example, involves exercises with extremely constrained rules for both metrical and harmonic structure, standard forms to compose, standard ensembles to write for, and so on. There are differences for musicians whose focus is performance over composition — but the best musicians, across genres and forms, are also students of what has come before and what works well and what does not. Mature composers and performers can go “off the rails” because, again, they know where the rails are and what they are for. Exactly the same applies to typographers and designers.