stefano, I never would’ve thought anyone would bring up something I could speak to with such ease at RI. Lo and behold. So, I gladly attempt some answers for you. If I’ve not connected some dots, or if my descriptions are too complicated, feel free to ask me for clarification. Most often, writing complicated ideas is a forte for many RI writers, but not always done well by me. You know?stefano wrote:... I don't know anything about music but is that plaintive kind of slip between octaves (is that what it is?) called something?
First, I’m unsure of the definition of your term “slip,” so, for the moment, I’ll define it as a thoroughbass; or a theme or passage of music that moves smoothly, easily, quietly, gradually. Then, your word “plaintive” meaning sorrowful, mournful, melancholic could describe from my point of view the feel of music that is accompanied by the thoroughbass. In Big City Life video, the rapper is accompanied.
Secondly, I’ll not neglect the definition of an octave, and it’s very good of you to bring up that word. It is defined as an interval made up of 12 semitones. One semitone would be the distance on the piano or electronic keyboard between a white key and its adjacent black key; or the distance between a black key and its adjacent white key; or, in two places on the keyboard you’ll see two white keys without a black one in between, the interval of which would be one semitone. So, all intervals less than 12 semitones apart would be considered within one octave. There are only four notes in the bass line composed for Big City Life video, and all those notes are within an octave. Simply put, had anyone of those four notes been placed elsewhere in the composition, then the bass line would’ve spanned, say, a couple of octaves.
I hope that’s been pretty clear, so far. Here’s a whole page on Music Theory/Scales and Intervals.
Now, thirdly, here are more specifics about the bass line, itself: it’s called by some schooled performers and composers Basso Continuo or Continuous Bass devised during the Baroque period 1600-1750; and, the line may be referred sometimes as thoroughbass. A continuo is a bass line composed of a certain number of notes, each of a certain interval from the previous note, played sequentially, and that sequence begins again once the previous sequence has been completed. Consecutive sequences are played as a thoroughbass throughout an entire musical work, or section of a work; usually, but not necessarily in all musical pieces incorporating a thoroughbass, composed for and played by the lowest pitched instrument.
As stated above, in Big City Life there are only four notes played sequentially in the thoroughbass, and, with a couple of exceptions, that bass line sequence is repeated monotonously till the end, which to my ears is uncreative. That bass line could have been softened with additional instrumentation, or halted for some time to give the listener a rest. However, I think the bass line, as proper as it already is, played against and starkly contrasting the rapper’s vocal line IMO well suits the lyrical and visual ethos of the video. Would you think so?
I do hope that’s been understandable.

~ A.
- Here’s a repeat of the vid talked about.
Big City Life | music video