Saidi, from the Sa'id (Upper Egypt): dum tek – dum dum – tek –. Against maqsum, the tek on the and-of-2 becomes a dum, so two low strokes (conga-lo) sit back to back on the and-of-2 and beat 3 — the rhythm's signature thump. The teks (conga-hi) fall on the and-of-1 and beat 4, with ka fills (rim) and riq (hat) eighths.
It accompanies tahtib, the stick dance, and the cane dance (raqs al-assaya), traditionally with mizmar and tabl baladi. The piano and bass stand in for the mizmar drone and ostinato in maqam Nahawand on C (C D Eb F G Ab B), exact in 12-TET.
Listen for the back-to-back dums: they push the bar's weight into its middle.
Practice: play saidi, then maqsum; the difference is one stroke, on the and-of-2.