been stressing over this for a while. many songs have a pickup or drum fill or count in before the song's first measure actually "starts" in reaper, i was stressing because if i included that, the entire timebase for the project would be +x (length of pickup). however, i found in the project settings a way to create negative values for the first couple of bars so that one's song can start right at 1.01.00 where it belongs. take a look, if you're like me, it'll make you happy. nym