I'm transcribing a score by Marc-Antoine Charpentier, and I've come across a passage in 3/2 time where long sequences of minims (half notes) are beamed together. Not just pairs, which I'd assume indicated tremolos, but sequences of 4 or 6. From the beat counts, I assume the intention is that they be equivalent to crotchets (quarter notes), but for authenticity I'd like to transcribe them as beamed minims (with crotchet durations). Is that possible in Sibelius?
You can enter the minims under a 4:2 or 6:3 tuplet and hide the tuplet bracket. (Or you can define a new crotchet notehead to look like a minim.)
Then there's a beam in the Lines menu which you can drape across the stems (switch off magnetic layout). It's quite fiddly, you'll need to play with the stem lengths, and it won't be very stable under any respacing.
Alternatively if playback is not important you could write them as quavers with a redefined notehead like a minim, hide the quaver rests in between, and beam them together in the conventional way.
No, this will be French Baroque "white notation". A white notehead with one beam = a modern quarter note, with two beams = an eighth note, etc.
Interesting piece of trivia: this was invented when paper began to be used for music scores rather than vellum. Ink on paper tended to soak in and spread, and the standard square and diamond shaped black noteheads that were in use turned into indistinguishable fuzzy blobs. So somebody had the idea of using open note heads rather than solid ones.
Defining new noteheads in Sibelius is probably easier than endless hidden triplets.
If you could write the music you want to see by hand on a piece of paper, scan it, save it as a png or jpg, and upload it here, then we could probably help you to create what you want in Sib.