A childhood belief about pop stars

I used to believe that, when a name appeared on a record, that person was responsible for every sound on it (of course, that would be true for Stevie Wonder, Paul McCartney and Prince, not to mention sometimes Danielle Dax, but I digress...). Unlike Hasil Adkins, however, I did not try and play guitar and drums simultaneously as a result. I think I figured out there had to be some kind of trickery involved (though I still used to wonder how Joni Mitchell managed to sing two lines that overlapped in 'Big Yellow Taxi' - VOCAL overdubs never dawned on me...).