I'll jump in this discussion as someone who never really understood the negative bars request, but has now completely come around and it is a worth while request. After we're finished a song or track, there may be some other things we need/want to do. For some film purposes, we've added vocal tracks before the track as cues or lead-ins such as in how we used to use bars and tone for videos. The other is when we use our songs in a live on-stage purpose... We have some songs with strings or electronic pieces that we want to be triggered live for the band to build a bigger show or MIDI to control lights. With a completed song, you have to produce the song and export it for recording beginning at the start. TO add vocal cues or lead-ins, you now have to shift the 'song' a certain amount of measures to the right. You either end up with 2 separate files or you try to keep shifting the song back and forth for export versus for live use. While it's not necessary and is a feature that a minority of people will use, I do now see WHY it is being requested. It would help in certain situations to be able to do it.

I personally would love this, best sonar feature request ever IMO.

This thread is self repetitive, to say the least, so I repeat myself as well. Some say they want  "sub-zeros" some say two empty bars will do.

The "sub zero" alternative, though, is the one that allows you to count measures and structures "real time" without extra math. If you make a song with 4 measure intro, 12 measure verses etc. and you have those structures in your head, it's annoying to go " ok, I change that thing in measure 11, which means it's actually measure 9....".