This one is so simple. I know I’ve created upbeats before. However, the time signature is 3/2 and first bar has three quarter notes. Clicking the popup (Shift M then 3/2, 3q) does not work. If I don’t have the time signature in yet, it only puts in 3/2 as the time signature, and the rests are still present.
You define the length of a pickup bar in terms of the time signature’s denominator. In 3/2, that’s a half note. Three quarters is 1.5 of a half note. So it should be Shift-M, 3/2,1.5 Enter.
(The ‘3q’ terminology will not work here, that’s for the Shift-B popover.)
Why not make it a decent feature request. I’d like the option to not have to do math to have the right upbeat. Suppose I’d need a 3/2 with, let’s say, a 3/16 upbeat, I’d rather just type 3/2,3x than having to calculate 3/2,0.375 (off the top of my head, I’m not sure it’s even correct).
It would be courteous to give @hrnbouma the solution check, since that is the post that answered your query. Giving that post the checkmark would also attach the answer to your difficulty right below you original query to help others who have your problem.