Percussion is the secret weapon that producers use to give motion to a song. Sometimes the percussion is obvious in a mix, and sometimes it's almost imperceptible (like the shaker on Tom Petty and the Heatbreaker's big hit "Refugee"), but it almost always makes a big difference how the song feels.
For decades now garage bands have been playing The Guess Who's "American Women" and wondering why it didn't sound like the record, and the reason is they're not playing the percussion that's an integral part of the song.
Take a close listen to the following video and you'll realize why it's almost a different song without the conga and tom hit.
Note that they're not playing totally in the pocket, but that was the state of production for the era, when timing wasn't scrutinized as closely as it is today.