Re: make \breath (kind-of) ignore clef change

[Kieren MacMillan]

Hi Jean,

> I'm not sure if the NR is the best place for explaining
> \propertyTweak.

I didn’t know of this until David K helped me build my \ignore functions, e.g.

 ignoreH =
   \propertyTweak horizontal-skylines ##f
   \propertyTweak extra-spacing-width #empty-interval
   \etc

> Its usefulness is basically to be a helper
> for defining "dual" commands like \shape, \footnote, \omit,
> or (in 2.23) \parenthesize.

Can I ask why one wouldn’t just always use this? e.g. What would be the benefit 
of choosing to define a “vanilla” \tweak, when \propertyTweak would also work 
in the other situation(s)?

Thanks,
Kieren.