Slipknot - (sic)

Recording: Slipknot (1999), digipak album 

I transcribed all music used in this post. The characteristic heavy distortion of heavy metal can be a big obstacle during the transcribing process. I apologize in advance if there are any errors.

DEVELOPMENT OF RHYTHMIC UNITS

While the key remains the same throughout the song, it's interesting to follow how the bass riffs develop over time. There are two rhythmic ideas which I have labeled A and B below. "A" contains two dotted eighth-notes and an eighth-note. "B" contains three dotted eighth-notes, followed by a quarter-note and a single eighth-note at the end.

There are 5 riffs based on the rhythmic unit A. They are labeled according to the order they appear starting with the opening riff as A1. A2, A3, and A3' are variants of A1. Two additional pitches are added to A2 (Eb, Db), and an E is added to A3 and A3'. From A2 to A3, the very first note of the riff is moved up to a Db resulting in an appoggiatura and the E adds chromaticism to the riff. A5 contains an augmentation of rhythmic unit A. When the sixteenth-notes are organized in groups of 6 and 4, you will get two dotted quarters followed by a quarter, which is the double length of unit A.

The second rhythm unit used in this song is B, and the first riff is B1 which appears in the video above at 1:52. It consists of three dotted eight-th notes, a quarter note, and a dotted eighth-note at the end. B2 appears at 2:09, B3 at 2:11, B3' at 2:21. The four variants on the rhythm unit B all consist of four dotted eighth-notes and a quarter. The order of these five elements change.