The statues depict Amenhotep III, the pharaoh whose reign in the fourteenth century BC marked one of the wealthiest, most opulent moments in Egyptian history. He set them as sentinels at the gate of his mortuary temple, a complex so vast, around 35 hectares, that no later pharaoh ever matched it; even Ramesses II's Ramesseum and the Temple of Karnak as it then stood were smaller. There the king was worshipped as a living god. Today almost nothing of that temple remains. It stood at the very edge of the Nile floodplain, and the river's annual inundation gnawed at its mud-brick walls year after year, while later rulers carted off its stone for their own monuments. The colossi endured because they were too colossal to move, and so they sit now before an empty field, guarding a memory.

Each statue stands about 18 metres tall, platform included, and weighs an estimated 720 tons, carved from blocks of hard quartzite sandstone. The stone did not come from nearby. It was quarried near modern Cairo and hauled some 675 kilometres overland to Thebes, the blocks too heavy, it is thought, to float upstream against the current of the Nile. How the Egyptians moved them at all remains a genuine engineering puzzle. Amenhotep, seated and gazing east toward the river, rests his hands on his knees; carved against his legs are smaller figures of his mother Mutemwiya and his great royal wife Tiye, and on the sides the Nile god Hapi binds together the plants of Upper and Lower Egypt. So large are the figures that they can be seen from more than ten miles away across the flat valley floor.

The singing began with a catastrophe. An earthquake in 27 BC shattered the northern colossus, cracking it and toppling its upper body. Soon after, the broken statue started to make its dawn sound, and the Greeks, who had long since renamed the figures after Memnon, a hero of the Trojan War and son of Eos, goddess of the dawn, heard in it the slain hero greeting his mother as she rose each morning. Emperors made the journey to listen. The science is less romantic but more remarkable: the note was almost certainly natural, produced as the morning sun warmed the porous, dew-dampened stone, driving off moisture and setting the cracked rock briefly humming. It was the sound of physics, mistaken for a god, and it worked only because the statue was broken.

The voice did not last. Sometime around AD 199, by local tradition, the Roman emperor Septimius Severus, who had visited the statue but failed to hear it sing, ordered the broken colossus repaired, its shattered upper tiers rebuilt in courses of fresh sandstone. The reconstruction was meant as an act of piety toward the oracle. Instead it killed the very thing that made the statue holy. With the cracks closed and the weight of new stone bearing down, the dawn note fell silent and was never reliably heard again; the last credible report dates to AD 196. The repair is still plainly visible: the lower body of the northern statue is one ancient block, while everything above the waist is a patchwork of later stone, a well-meant restoration that quieted a legend forever.