I'm trying to work on my guitar playing but, man, my musical ear is total crap. Plus I can never figure out how to tune out stuff like the melody and only focus on one thing at a time like the chords.
And my sense of rhythm is equally bad. I was surprised to see that "Somebody" and "I ain't..." don't start at the beginning of the measure. They start an eighth note before. Also I don't even know if that "mini-measure" of just an eighth has a specialized a name.
Ah....
It’s a pickup measure (or anacrusis) and it’s fairly common in pop music I believe.
Also useful for when starting from a midpoint while practicing a score.