Say I want to write a statement like this, but in a more compact form:
E♯ is the enharmonic equivalent of F♮
What symbol could I use instead of "is the enharmonic equivalent of"?
It doesn't seem right to me to use the equals sign = because the left and right hand sides aren't equal. The symbol should represent a qualified equivalence.
Or is the convention to "just hold your nose and use =" even though it's not actually true in the mathematical sense?
It occurs to me that we already use the equal sign in non-mathematical ways in music notation. For instance, the tempo indication:
♩ = 120
or the metric modulation:
♩. = 𝅗𝅥
Perhaps it's OK after all to use a plain equals sign to denote enharmonic equivalence. The tacit assumption is that the human reader of the notation will know how to expand the compact notation back into an English sentence.
I came across the decorated equals sign: ≑ which (to me anyway) conveys the idea that the terms on its left and right are sort-of equal.
Thinking about it, E♯ and F♮ are two different notations for the same physical property i.e. pitch. In the same way you could say:
"one two three" ≑ "un deux trois"
The reason I asked the question originally was that I was experimenting with the notation of Theoretical Keys. We'd most of us be comfortable with the idea that
F♯ is the enharmonic equivalent of G♭
F♯ ≑ G♭
6 sharps ≑ 6 flats
But what follows from this is this sort of thing:
10 sharps ≑ 2 flats
12 sharps ≑ 0 flats
The use of an equal sign in these statements looked plain wrong to me.