Think of ancient Greek verse and what often springs to mind are those great beacons of literary achievement, the epics of Homer, the odes of Pindar, the dramas of Aeschylus, Sophocles and Euripides, the lyrics of Sappho. But the canon is only a reflection of the limits of our knowledge; vast swathes of ancient literature do not survive, and there are whole realms of cultural activity that never even got as far as a manuscript, leave alone the opportunity to withstand history’s vicissitudes. New research suggests that there was a substrate of more demotic, more everyday verse that has remained largely invisible to modern eyes.

Prof Tim Whitmarsh of the University of Cambridge has examined a short verse that survives not because it was copied down by Byzantine monks, preserved through the medieval age then “rediscovered” in the Renaissance, like much canonical classical literature, but because it was inscribed into semi-precious stones as cameos, and, in one instance, scratched on to a wall as a graffito.

There are various forms of the verse, which has been found on mass-produced, low-cost gemstones scattered across the Roman empire from Spain to Hungary to Mesopotamia, roughly dated to the second and third centuries AD. Spoken aloud in Greek, the verse trips off the tongue, and even in English, it’s hard not to read it almost like the lyrics of a pop song, with its open-ended, simple, adaptable-to-any-situation sentiments: “They say/ what they like/ Let them say it/ I don’t care/ Go on, love me/ It does you good.” (It can apparently be sung very nicely, in Greek, to the tune of the chorus of Chuck Berry’s Johnny B Goode.)

In fact, Prof Whitmarsh argues that the Greek verse can be best understood as using a stress-based metre, just like much modern English poetry and pop lyrics, the rhythm of which arises from the accents that fall on certain beats. Were he correct, that would pull back the known history of Greek stress-based poetry by several hundred years. Surviving poetry from Homer right through to the verse of the Hellenistic period employed a quantitative system based on syllable length, with Greek stress-based poetry appearing only later, in the medieval era.

But quantitative verse forms reflected the Greek language as it was spoken only in the archaic and classical periods. From around the third century BC pronunciation changed. Long vowels stopped being pronounced, and the language moved gradually towards the way Greek is spoken today. Poetry, or the kind of poetry that entered the canon, continued using the older forms that no longer reflected the ordinary spoken language. Prof Whitmarsh thinks it highly likely that many demotic, everyday verses – like “They say/ what they like” – would have been circulating orally, though, during the period.

Having a necklace inscribed with the lines might be something like a modern quote T-shirt, where the wearer is signalling something particular to a group of people in the know. Usually classed as an inscription (because of the way it has survived, carved into gemstones), the verse has not been much examined as poetry before. Sometimes discoveries can be hiding in plain sight: it all depends where you are looking, and what you are looking for.