Peter Oxendale is one of the world's premier forensic musicologists and is frequently sought after in cases of music ownership and plagiarism. 

"Every songwriter is partly a product of their influences," Oxendale said in a recent New York Times profile. "Allowing yourself to be influenced by a song — just not copying the melody, chords or lyrics — is perfectly fine."

But sometimes those influences are taken a step further, and lines from songs get appropriated and reused in new ones.

The most recent Collector's Crossroads episode examines songs that tread the thin line between homage and outright theft.

Check out the playlist below.

Collector's Crossroads airs on CPR's OpenAir Thursdays at 3 p.m., Saturdays at 6 p.m. and Sundays at 4 p.m.