Hocus Pocus in no doubt Focus's best known song (although people often know the song but not who did it). Various versions are available.
There are at least 14 versions by Focus or by Akkerman or van Leer playing solo. These are
1. The original opening track on Moving Waves (1972)
2. The edit from that for the original single, now on The Best of Focus (1972)
3. The fast version or US single available now on Ship of Memories (1973)
Various live versions by the early band are around including
4. The live version for TOGWT on Masters from the vaults DVD (1973)
5. The live version on At the Rainbow (1973)
6. The live reprise on At the Rainbow (1973)
7. The live version featuring Philip Catherine on Live at the BBC (1976)
Then there is
8. Thijs van Leer Nice to have met you (1977)
In the late nineties Akkerman began to play it again live (without the yodels) in different forms.
9. Jan Akkerman 10,000 Clowns on a rainy day (1997)
10. Jan Akkerman Live at the Priory (1998)
11. Jan Akkerman Live at Alexander's (1999)
The reformed Focus can also be heard on at least two live recordings
12. Focus (with Jan Dumee) Live in America (2003)
13. Focus (with Jan Dumee) Live in South America (2004)
14. It is also on Golden Oldies (2014)
Also note this rather funky version
14. Jan Akkerman Fromage a trois (2006)
A number of covers have also appeared. The title Hocus Pocus is used for several songs but these are all covers of the Focus number
1. The Vandals a punk band appear to have been first on When in Rome do as the Vandals 1984
2. In 1987 an orchestral version was done by The Metropole Orkest conducted by Rogier van Otterloo
3. Fourth Estate a progressive band were next on Dustbuster Demos 1988
4. Gerdesits Ference a Hungarian tenor vocalist and rock singer covered it on the album Os-Metal in 1989.
5 Michael Fath covered it (without yodels) on the album Song Tapestries in 1990.
6. Spies who surf did a surf rock version on a compilation album 20 Explosive Dynamic Super Smash Hit Explosions! 1991
7. Gary Hoey had a big hit with it. It first appeared on his Animal Instinct 1993 [live versions can be heard on his Hocus Pocus Live 1998. Also check out Wake up call 2003]
8. Vanessa-Mae the violin playing oriental prodigy on Storm 1997
9. Helloween the Swedish or German heavy metal band on Metal Jukebox 1999
10. The Paul Green School of Music on the Rock School Soundtrack 2005
11. Iron Maiden had a version out on one of their Different world packages 2006
12. Marillion covered it on a special album called Friends 2007.
Some versions are great, some not so hot. Often one finds new aspects of the song being explored. The heavy metal one is obvious, the eastern feel (that Vanessa-Mae really goes for) less so but the classical dimension you might not have noticed until you hear the opening to Gary Hoey's live Hocus Pocus (Insanity Mix). Akkerman's different renditions over the years have shown quite some variation. The current Focus line up have turned the song into a showcase for the undoubted talents of Pierre van der Linden.
PS Kell Nordli has kindly pointed out that the Metropole Orkest orchestral version (arranged by Henk Meutgeert) is featured on a double LP 'Made in Holland' (1987).