How do you count Black Dog by Led Zeppelin?

I heard it several times now, and my ears are generally good. I work as a music teacher. The note sheets I've seen count the guitarphrase in on a 2/4 measure and places a 5/4 measure just before Robert Plant starts singing. But, but, but. Orksecurity is right about listening to the drums. If you listen carefully John Bonham (the drummer) gives a sign to the rest of the band in the end of the vocal phrases. I really don't know how to measure it, but it is definetely not 4/4 all through.

I hear it as 4/4 all the way through, with pick-up phrases and some syncopation that can mislead you about where the beats actually land. Tap your way through it, listening to the drum to stay on beat -- and don't worry overmuch about the fact that things get get loosey-goosey when the drum is absent; the vocal is sung relatively free and often starts a beat early, overlapping the previous instrumental response. The guitar and/or drum lick after each vocal line is what counts the rest of the band back in on the rhythm. (da)-Dum da DUM - (da)-Dum da DUM - (da)-Dum da DUM - DUM - DUM - HTH...