Some experiments, with "=" in font-family:musicalsymbols:

font-sizes: 15 to 71 in 4px intervals:
= = = = = = = = = = = = = = =
font-sizes: 3 to 16 in 1mm intervals:
= = = = = = = = = = = = = =
font-sizes: 8 to 47 in 3pt intervals:
= = = = = = = = = = = = = =
font-sizes: 0.12 to 0.72 in 0.05in intervals:
= = = = = = = = = = = = =
The printed page is slightly better than this.
Lesson learned: Don't use ===to draw staves. (Note the gaps too.)
So now we try it with stv.gif
font-sizes: 15 to 71 in 4px intervals:

font-sizes: 3 to 16 in 1mm intervals:

font-sizes: 8 to 47 in 3pt intervals:

font-sizes: 0.12 to 0.72 in 0.05in intervals:

Even worse - looks like they will have to be done one line at a time.