If you watched Jay-Z's barnstorming set at Glastonbury, you'll have noticed that he took a cheeky swipe at those who had said that he didn't belong at a rock festival by throwing the riff from AC/DC's Back In Black into a reworked version of 99 Problems.
This followed a ramshackle cover of Oasis's Wonderwall, which came in response to Noel Gallagher's less than enthusiastic reaction to the news that Jay-Z was to headline the Pyramid Stage.
As you may know, 99 Problems has been remixed many times before, most notably by Danger Mouse, who married it to The Beatles' Helter Skelter on his Grey Album. There are also versions featuring Linkin Park, Nena (the 99 Luft Problems remix incorporates 99 Red Balloons and demands to be heard) and even Jimi Hendrix (the song has been mashed together with Voodoo Chile).
In fact, the list goes on and on â Red Hot Chili Peppers' Give It Away and Bon Jovi's Wanted Dead Or Alive have also served as the backing to the 99 Problems lyric.
So, why so many remixes? The answer is simple: when Jay-Z released the Black Album, which 99 Problems is taken from, he also put out an a cappella version, so anyone who wants to put their own stamp on the record's songs can easily do so. It's still available to buy, so go and pick it up if you want to add your mash-ups to the delugeâ¦