In Learn A Song Mode - you can sort by "recommended" - which is what I use most - usually when playing the recommended song - I will play it two or three times, this does have you jumping tunings frequently - but I've found it does a good job of challenging me.. My drawback with following that route is that I have a bunch of songs at 50% - and no real mastery of any song..at this point I am still very much a novice, so I am ok with that right now as I feel a broader exposure to musical styles and techniques is what I need - when I get a good chunk of songs to say 65-75%, my plan is to go back and revisit songs to be more focused and get a personal library of stuff up closer to 100. I know repetition is required, and at this point my learning is scattered - but I know I have a lot to learn and its still an open book.