C# Persian on Guitarrón
Every C# Persian note across 6 strings, roots flagged, read as bass material.
C# Persian runs 7 notes to the octave. Below it is mapped onto this instrument's A–D–G–C–E–A fingerboard with every C# marked, because what a player needs mid-number is not the pattern but where the root is when the harmony moves under it.
Intensely exotic — two half-step clusters (b2 against the root, b5 against the 4) and a raised 7th make it the most dramatic of the world scales. Mysterious, ornate, and tense.
Heard in: Persian and Middle-Eastern-flavored melodies, film scoring for desert and ancient settings, and exotic metal and progressive-rock riffs.
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 Db and let the written line pick its own notes out of it.