Cutting long movie into clips

Hello - I have a video of concert footage that is 83 mins long, and I am trying to split up into individual songs. When I try to select a clip using R the scroll bar won't scroll past the end of the window. Is iMovie not designed to work with such long videos? Is there a way to enter the timestamps for the in and out points directly instead of clicking and dragging? I am new to iMovie - so let me know if I have missed something obvious.