It should take 4.5 to 6 hours to finish without breaks. On tips to get that achievement, try to eat small snacks like cereal bars or chips when you're hungry. It you need to go to that bathroom try to wait to get to a song that has a large gap and go quickly, a diaper may also be helpful. If you have a wireless, make sure you have enough power to last you through the set list. Be careful you don't touch the xbox guide button or the pause button and if you play with someone make sure they do the same. You may be tired once you get to the last couple of songs. Just muscle through them and you will be fine. Good luck