Arabic maqam music is built from ajnas (singular: jins) the way Western modal theory is built from tetrachords — a short melodic cell, usually four notes spanning roughly a fourth, that two of them join at a shared tone to make a fuller scale. A maqam is not one fixed set of intervals so much as a named way of stacking two or three ajnas, and a player's ear tracks which jins a phrase is currently living inside far more than it tracks a Western scale degree.
Most ajnas lean on an interval no twelve-tone equal-temperament instrument can produce at all: a neutral second or neutral third, sitting roughly halfway between the minor and major version a fretted or keyboard instrument knows. Rast, bayati, sikah, and saba — four of the most central maqamat in the whole tradition — are built from exactly this kind of jins. A twelve-position chart of any of them would not be an approximation so much as a different piece of music wearing the original's name.
So this page charts five ajnas and stops there on purpose: hijaz, kurd, nahawand, ajam and nikriz. Each is built entirely from semitones and whole steps, which means a 12-TET fingerboard can represent every one of their tones exactly, with nothing rounded off and nothing left out. Three of them are tetrachords, spanning a fourth; ajam and nikriz are pentachords, spanning a fifth, which is the tradition’s own shape for them rather than a liberty taken here. Naming the ajnas this site will NOT chart — and saying plainly why — is as much the point of this page as the tables below it.
The five ajnas, declared
Each jins below is declared as semitone offsets from its own root (0 is always the root). Everything else — which pitch classes it spells for a chosen root, and where each of those tones falls on all six oud courses — is derived from the registry, never typed in by hand.
| Jins | Offsets (semitones) | Positions on course 1, root C |
|---|---|---|
| Jins Hijaz | 0, 1, 4, 5 | 0, 1, 4, 5 |
| Jins Kurd | 0, 1, 3, 5 | 0, 1, 3, 5 |
| Jins Nahawand | 0, 2, 3, 5 | 0, 2, 3, 5 |
| Jins Ajam | 0, 2, 4, 5, 7 | 0, 2, 4, 5, 7 |
| Jins Nikriz | 0, 2, 3, 6, 7 | 0, 2, 3, 6, 7 |
The ajnas this page will not chart
Jins rast (the backbone of maqam rast) and jins bayati both place their second degree on a neutral second — narrower than a Western whole step, wider than a half step, and simply absent from any twelve-key instrument's vocabulary. Jins sikah goes further still: its ROOT is a neutral tone, so there is no honest twelve-tone position for the tonic itself, let alone its neighbours. Jins saba opens on that same neutral second and then closes to a diminished fourth, a shape whose character lives in the bend between positions rather than at any of them. A position map claiming to represent any of these four would be teaching a fingering for a different, better-tempered piece of music while calling it by the maqam's name — and that is worse than publishing nothing.
Those four are not just absent from this page, they are DECLARED absent: REFUSED_AJNAS in the engine carries each one’s real offsets, fractional intervals included, and scripts/validate-ajnas.js fails the build if any of them stops having a fractional interval, quietly acquires a position table, or drops out of the paragraph above. The refusal is checked in CI exactly like the tables are.
Reading a position table
Every leaf page's table lists all six oud courses and, for each one, every position within the twelve-position board where a tone of that jins (rooted on C) actually falls — position 0 is the open course itself. The numbers are recomputed independently from the registry's own tuning by scripts/validate-ajnas.js on every CI run, so a retuning of the registry could never leave a stale table standing uncorrected.
Where to start
Start with jins nahawand — its natural-minor shape will already sound familiar, which makes it the easiest place to hear how a jins behaves differently from a scale: it is a cell to move THROUGH, not a home key to sit in. Then jins kurd, whose Phrygian shape is the closest formal cousin a Western ear already owns, and jins ajam, which is more familiar still and reaches a fifth rather than a fourth. Jins hijaz and jins nikriz come last, and belong together: they share the same stretched interval and place it a degree apart, which is the clearest lesson on this page that where an interval sits matters as much as which interval it is. Run each one against the chord library for a Western-harmony comparison, and keep the tuner honest while you check each position by ear.