EDIT 2017: Sadly, the Wise Guys have split up, but their website is still available (although won’t be updated) and their music is still around, just search for them on YouTube.
Although yesterday I mentioned Tokio Hotel as a German band whose music results in lots of fans wanting to learn German, The Wise Guys are a band who I like to use for teaching.
The Wise Guys are a German a cappella band and not only do I like listening to them, I also find their lyrics useful in adult education. My favourite song is “Meine Deutschlehrerin”. It deliberately contains 21 grammar mistakes.
Can you find them all?