Bill Medley needs a caveat before anything else. As one half of the Righteous Brothers, he sang on some of the most celebrated records in pop history, including "You've Lost That Lovin' Feelin'" and "Unchained Melody". By any sensible measure he is anything but a one-hit wonder.
But our method looks at songs credited to him, and there one duet stands far above the rest. "(I've Had) The Time of My Life", his 1987 collaboration with Jennifer Warnes for the film Dirty Dancing, became a worldwide number one and won both an Oscar and a Grammy, carried by the movie's enormous and lasting popularity. It now sits near 590 million streams.
His other credited songs trail far behind on streams. Dividing the hit by his second biggest gives a ratio above 18, many times our 5.0 line.
So by our strict, numbers-only measure, Bill Medley registers as a certified one-hit wonder. We flag the caveat firmly: his work with the Righteous Brothers alone secures his place in music history, and one blockbuster-soundtrack duet has merely, on streams, outrun a legendary career.