You want to be able to learn complicated (even from other languages) songs? Try Chantez.de, where you kind of get your own teacher: YouTube sings first, then you sing together. (line by line)
If you want to, you can add your own favorite songs to the list, too. (when there are a lot of songs (>100) I probably will add a search system) You just have to type in the YouTube code for the video in the bar above, press space for each line, and then submit the last informations (just see the tutorial http://chantez.de#create).
92745834s ago, by Antonio