Breaking barlines temporarily?

How can I break the barlines in a group temporarily, e.g. for an aleatoric section?

I’m not exactly sure what you want. Do you want an open meter? If so, use Shift-M, X, Enter.

I want regular bars with group barlines followed by a section with barlines only within the staves (not through the systems). Then I would like to define aleatoric repeat sections individually for each part, i.e. a section of 6 quarter notes in the first part which should be repeated, a section of 9 quarter notes in the next part etc. Here the barlines should be interrupted. I know how to do this with polymeters, but not if all parts have the same meter. – I have created the repeat characters in the articulation area; do I have to use the x-time sig. and create manual barline-signs in the articulation-area?

You can change the barlines at any point using a bracket and barline change:

For your aleatoric sections in individual instruments, you can use staff-specific time signatures and/or barlines by typing Alt+Return when you confirm the Shift+M popover to create the time signature.

Got it. But this way I can only change the barline-connection at the beginning of a system, not in the middle of it, right?

That’s correct, yes.

So the only solution is to insert a graphic line as a barline (see screenshot)?

Looks good, although logically that graphic barline and meter are still shared by everyone. Would you put barlines on different beats later on in the open section?

Or try giving each staff an independent open meter time signature (independent = close the popover by pressing Alt/Opt-Return, not just Return).

Thank you, yes, I know that, but what if I have simultaneous barlines?

What do you mean by “shared by everyone”?
Yes and no, I will put barlines partly on different positions, partly on simultaneous positions. I intend an aleatoric passage in Lutoslawski-style.

I mean since everyone (in that screenshot) has the barline in the same place, I wondered why you want to break it. With Lillie’s suggestion of independent meters you can put barlines anywhere you want and they’ll connect only where they coincide.

In the meantime the systems are filled up and look like this. I am not sure if I want a connected barline at the end of the first system since this would suggest a synchronisation which is not intended.

Ah, now I see! Thanks for the illustration.