Hi, I've been practicing the "spider riff" from MOP by Metallica, and kinda noticed that some of the notes used are not the chord tones of Em, even though the chord progression of that part is Em (at least according to the score I have by cherry lane lol). The riff goes like...EFBE FCEF C#EFC EFBB.... I believe that the notes F, C and C# are not the chord tones of Em, since the notes making up Em are E, G and B. Can any of you bass masters guide me on where those non-chord tones come from? Do they come from the scale with which the song was written or else? (I'm like....on which key the song was written in the first place, lol). Thank you so much for your attention.