D Rock 'n' Roll on Guitarrón

D Rock 'n' Roll runs 6 notes to the octave. Below it is mapped onto this instrument's A–D–G–C–E–A fingerboard with every D marked, because what a player needs mid-number is not the pattern but where the root is when the harmony moves under it.

Major pentatonic with a b3 rubbed against the natural 3 — bright and bouncy with a bluesy smirk. Playful, swinging, and built for boogie riffs.

Heard in: Fifties rock, rockabilly, boogie-woogie, Chuck Berry-style riffs, and jump blues.

The bass takes almost no melodic line, and that is precisely why these matter: the notes between one root and the next come out of a scale, and an approach that lands wrong is the loudest wrong note in the ensemble.

Take it slowly against the playback until the geometry stops being geometry, then put it under a number in D major or minor and let the written line pick its own notes out of it.