Here's the phrase I'm working on, a nice chord progression from the finale of a symphony movement (Dopper 7 mov. 1) that I'm arranging for solo piano.
So the B♭ trill in the right hand exists for most of this phrase, but it's not the important part; the fortissimo chords are what the section is all about. The trill is "background noise", pardon my French. So it can be interrupted, as it is in ms 4 and 6, to get the big bold chord in.
I've currently notated this with an eighth rest and make the trill pick up after with a double-dotted half note. This works but I'm not sure if it's the best way; because I am notating two exact durations when really I don't care about the duration much. If a performer wants to let the chord breathe for a quarter note before resuming the trill, that's fine. If they are an acrobat and want to make the jump in the duration of a semihemidemisemiquaver, I say let them do it.
A grace note offers this freedom of duration; the left-hand grace note in ms 3 can be of any short-ish length (and can even be left out in this case) - and it also doesn't affect the length of the note/chord it leads up to. I'm wondering if there's something similar I can notate to interrupt the trill for just a small portion of time to get that chord in, without specifying the duration.
The two options I'm thinking of are: to not notate a rest for the trill at all (letting the performer figure out that it should be interrupted), or to add a tied grace note to every single note on that beat except for the trill.