I dunno what a herrmid is but i do know that i want more of them

Yes! Although the concept of lietmotiv became a more formal concept through the works of Richard Wagner, and Guiseppi Verdi!

But the idea and formal processes date back to the baroque or possibly even midieval eras. The most prominent examples i can think of fall under the form of fugues. Where a melody is written and strictly immitated and developed using a "set of tools" like augmentation, dimenution, and inversion to name a few.

I would imagine that many forms of non western folk music also relied heavily on the idea of a theme so as to be easily passed down orally, but I'm speculating. Non western music history is still a bit outta my wheel house.

Im offering my perspective as a music scholar here but there is a specific terminology for the element of music that becomes an ear worm. You can call it a theme, melody, or hook but entire pieces are planned around it. In classical music the entire genre of symphony is devoted to exploring the possibilities of said theme.

Hop this helps or something whatevs ams a 40oz deep... discover classical music!