setting specific time length
I'm relatively new to REASON, I've been using it for a few months to make tracks for some videos I put together, mostly abstract stuff. But I've run into an issue where I need to set out a specific amount of time to work with, I don't quite know how to set it to work within lets say 2 minutes and 20 seconds. For a specific video I'm doing I need a background abstract noise track, ambient type stuff, but I want to organize it so it starts dropping a few sounds and instruments near the end, and I can't do that specifically until I know how to figure out how much time I'm working with.
Hard to explain something so simple... sorry, but any help would be great, I'm sure it's a simple thing to figure out but I can't grasp it at the moment.