Twelve keys, evenly spaced.
Music software divides the octave into twelve equal steps of 100 cents. Piano rolls, MIDI, tuners and pitch correction are all drawn on that grid. For most Western pop it never gets in the way.
Rast does not fit.
Play Rast from C and the third note, sikah, lands near 350 cents, halfway between E flat and E. The seventh, awj, does the same between B flat and B. A piano has to choose a key, and neither key is the note.
The note moves.
Halfway is how sikah is written, not how it is played. Musicians place it a little higher or lower depending on the maqam, the city and the phrase. No fixed grid catches that, however fine.
Twenty four is a map.
Many musicians write maqam in 24 quarter tones, and Cairo has argued about that scale since at least the 1932 Congress of Arab Music. It is a useful map. The ear still has the final word.
How producers work around it.
Pitch bends drawn note by note. Synths retuned by hand. Vocals recorded live, with pitch correction kept well away, because left on, it snaps sikah to E flat or E.
Hear the difference
Sound only plays when you press a button.
Hijaz sits close to the piano. Rast and Bayati do not.