Does lilypond have the ability to typeset bars in free or open time?

Question

I'm using lilypond to arrange a new part for concert band by combining/picking and choosing from a couple of different parts that need to be covered, but we don't have instruments for on the originally scored instrument.

Does lilypond have the flexibility / a way to enter into a period of open or free time?

I'd like to mimic the X that is typically shown in concert band score when entering/changing into free or open time and using annotations to indicate the guidance the composer has provided. I realize this will not be part of the midi that lilypond can be asked to produce, but that's fine, at the moment, I'm just typesetting a couple of parts.

I've pored through the documentation for time signatures and special concerns but I've not found any indication that this is possible. I've seen questions that ask how to hide the time signature, but this isn't quite the same.

Answer 1

Usually this is done via cadenzas. The lilypond index term is "unmetered music", described here.

Note that this will only turn off barline insertion and bar counting. It doesn't do anything else; for instance, if you want a smaller font size during the cadenza or some markup text, you have to insert it yourself.