When I try to increase the tempo of a completed project, it creates a vibrato effect on all the instruments, esp noticeable on the bass. Just 3-4 clicks up is enough to create this and make it unusable. Why does this happen? Thanks! T

Hi T - Instrument tracks should automatically follow any Tempo changes, but if you also have audio tracks in the Project, make sure you enable Flex on all of them ["E" > Editor pane > Track > Enable Flex], otherwise they'll get out of sync with the Instrument tracks -- if that was the case a Tempo change of a few bpm could potentially cause the effect you referred to..