When I first heard this expression, I decided it was a philosophy that could easily be applied to music. It means, simply, that as drummers we can lead or follow or work unobtrusively in the background.
One of the best examples of a drummer who leads is Buddy Rich. Yes, it was his own band, and of course he led it from behind the set. Another leader, oddly, is Charlie Watts. From the opening notes of any Rolling Stones tune, it's quite evident that Charlie is in charge.
Staying with our theme of ‘60s relics, two not-too-obvious ‘followers’ are Keith Moon and John Bonham. Despite all the flash and bravura, these guys sat on their band mates’ coat tails. Keith Moon followed Roger Daltry; John Bonham took his cues from Jimmy Page.
You might think that getting -- or staying -- out of the way would be a bad thing, a sort of non-performance. Again an unexpected example: Vinnie Callaiuta. Monster player, but a lot of the time he's very nearly invisible. Whether he's backing up Paul Simon or Jeff Beck, he works subtly in the background, content to let the music come first.
Of course on any given gig, the drummer can move through all three roles, depending on the music, the ensemble’s needs and, naturally, the mood. If the band is struggling to lock things in, a strong drummer can take the lead and help sort things out. If the band has a strong leader -- the vocalist, for example -- the rest of the band can pick up on his/her direction and run with it. And when the whole band is grooving, just settle back and enjoy the ride.