Today I was looking at a solution to sort my portable music by year, I find it really stupid that the most sold music player in the world doesn't allow to do so. After almost half an hour of searching I found this absolute gem I need to share. It's called iPodYearSort, it's a little old (made in 2007) but it works wonderfully even with the latest iTunes and iOS firmware.
This is the page, you can find every info there: http://www.pretentiousname.com/ipodyearsort/index.html (http://www.pretentiousname.com/ipodyearsort/index.html)
edit: I don't know which is the right section for this thread, I guessed AAC - General since it modifies AAC Tags.