From the Dangerous Minds archives:

“Hocus Pocus” was an AM and FM radio hit for Dutch prog-rockers Focus, straddling the line between avant garde and just plain silly. Focus, you might say, were one of the few prog rock bands who didn’t take themselves so seriously. How could they with a signature tune like this one?

Although “Hocus Pocus” was originally released in 1971 on their Moving Waves record, it didn’t really become a hit until 1973 when they re-recorded a faster version for release as a single. Of course, it’s unlikely that any song which could be (accurately) described as “heavy metal yodeling” would ever get radio play in the first place, let alone become an absolute worldwide smash, but improbably, that’s what happened.

“Hocus Pocus” takes the form of a rondo, meaning a central motif (in this case the guitar riff) keeps returning as drum, flute, accordion and guitar solos each, in turn, take the spotlight. The lyrics are just gibberish. It might be the most elaborate hit single, either before or since Queen’s epically ridiculous “Bohemian Rhapsody.”

When Focus would perform “Hocus Pocus” live, the group would play the tune even faster, with each member of the band taking an extended solo. I admit to being the proud owner of not only Moving Waves, but also their live album, Focus at the Rainbow, which includes an eight minute-long version of the song. Many people will know the tune because it was used in a Nike commercial shown repeatedly during the World Cup in 2010.
 

 
Here Focus seen are performing their biggest hit on The Midnight Special in 1973:
 

 
Here’s Focus live at the Rainbow in London, 1973. A crazy 8-minute-long “Hocus Pocus” starts at 4:42: