Classic hip-hop bass is a sub-bass locked to the chord roots of the sampled harmony

In classic (non-trap) hip-hop the bass is a round sub-bass (or upright bass) that plays the roots of the current harmony — the chords implied by the chopped sample. Locking the bass to those chord roots (bass-harmony-lock) makes the low end reinforce rather than fight the sampled material, which already carries the harmony. Because the sample supplies the chords, the producer’s bass job is mainly root-following: hit the right root under each chord of the loop, kept clean and mono for a solid low end. This is distinct from the trap 808, which doubles as a pitched low-tom rather than a steady root-follower.

Examples

Strudel: read the root of each chord in the chopped loop and play sub-bass on those roots (bass-harmony-lock) — e.g. a sine on the chord roots under a chopped Rhodes sample.

Assessment

Given a chopped soul loop that cycles through two chords, write a sub-bass line that root-follows the harmony and explain why locking to the sample’s roots (rather than a free bassline) suits classic hip-hop.