We attended an early music concert today featuring 13th century French music. To play music from that era, the musicians have to take great liberty in reconstructing the tunes from scarce source material. Sometimes they have nothing but the words, sometimes musical notation or side notes specifying instruments or style of play. Anyway, listening to one piece I was kind of like, "Congratulations, you've reconstructed Steely Dan's Hey Nineteen." The tune was identical.