In professional publishing, if you change a clef in the middle of a staff, does it go before or after the bar? Finale defaults to putting the clef before the bar, but it seems more clear to me to put it at the beginning of a measure. I don't want to commit to this only to be told later that it's a major faux pas.

Thanks!

Before the bar.

Generally before the barline is clearest, which, after all, is the essential thing in writing music, but there are occasions when you have to change clef where the music demands it, no matter where you are in the bar, (I speak as a cellist with 3 different clefs to choose from!) so I wouldn't get too hung up about it.

Sibelius also defaults to putting a new clef before the barline but you can then move it to the position you require.

Before the bar, its a heads up in a way, because naturally as you play a piece you will mentally read slightly ahead so you know what's coming, so as I said, its a "heads up, clef change coming."

It goes before the barline if the entire subsequent bar is in the new clef. If you want to change clef within the bar then it goes before the first note in the new clef.

Also, if the clef change coincides with a new line, the new clef needs to go at the end of the old line before the last barline.