Here is a quirk of American copyright law that shaped the sound of twentieth-century music.
You can copyright a melody. You can copyright lyrics. You cannot copyright a chord progression — it’s considered too generic, too much a part of the common language of music, to belong to anyone.
Bebop musicians in 1940s New York understood exactly what that meant. If the chords to a popular song were free to use, and only the tune on top of them was protected, then you could keep the harmonic architecture you loved, write a completely new melody over it, and own the result outright.
The technical name for what they produced is a contrafact. There are hundreds of them, and if you’ve listened to any bebop at all, you already know a dozen without knowing it.
What a contrafact actually is
A contrafact is a new melody written over the chord progression of an existing song. Same harmony, same form, same number of bars — different tune on top, new title, new composer credit.
The word itself is fairly recent. It was borrowed from the musicological term contrafactum, which described the medieval and Renaissance practice of setting new religious words to existing secular melodies, and applied to jazz by the scholar James Patrick in a 1975 study of Charlie Parker’s compositions. The musicians doing it in 1945 didn’t call it anything. They just called it writing a tune.
The money was real — but it wasn’t only the money
The royalty angle gets quoted constantly, and it’s true as far as it goes. When you record someone else’s song, the composer and publisher earn from it. When you record your own melody over their chords, you don’t owe them anything, because the chords were never theirs to charge for.
For musicians who were paid badly, treated as sidemen on their own sessions, and largely locked out of the publishing side of the business, this mattered enormously. But framing it purely as dodging a bill undersells what was going on. The point wasn’t only that beboppers avoided paying royalties. It’s that they started earning them. Writing your own head over familiar changes turned a working musician into a composer with a catalogue — and that shift, in an industry where sidemen got a flat fee and songwriters got paid forever, was closer to a quiet reallocation of power than a loophole.
There was a musical reason too, and it may be the bigger one. Bebop soloists improvised on harmony rather than on melodic decoration, which is what separated them from the swing players before them. The old pop melodies were, frankly, in the way. Stripping a standard down to its changes and building something faster, angular and more harmonically alert on top gave the band a launchpad instead of a song. The head told you what kind of musician was about to solo.
Ten famous contrafacts
Start with “I Got Rhythm”. Gershwin’s 1930 song has generated more contrafacts than any other piece of music in jazz, so many that its progression got its own name: rhythm changes. Duke Ellington’s “Cottontail” (1940) sits on it. So does Lester Young’s “Lester Leaps In”, recorded with the Count Basie small group in 1939 — proof, incidentally, that this practice predates bebop and that the boppers inherited it rather than invented it. Charlie Parker and Dizzy Gillespie’s “Anthropology” is the definitive bebop version of the trick. And more than a decade later Sonny Rollins wrote “Oleo”, recorded with Miles Davis in 1954, on exactly the same chords, which tells you how durable the framework turned out to be.
Then there’s Parker’s own run of them. “Ko-Ko”, recorded in 1945, takes the changes of Ray Noble’s “Cherokee” at a tempo that functioned as a barrier to entry — if you couldn’t play “Cherokee” fast, you couldn’t sit in. “Ornithology”, co-credited to Parker and trumpeter Benny Harris, rebuilds “How High the Moon”. “Donna Lee” is written on “(Back Home Again in) Indiana”, and comes with a long-running authorship argument attached: it was published under Parker’s name, but Miles Davis claimed for the rest of his life that he wrote it. And “Scrapple from the Apple” is a hybrid — Parker took the A sections from Fats Waller’s “Honeysuckle Rose” and bolted on the bridge from “I Got Rhythm”, assembling one tune from the spare parts of two.
Two more round out the ten. Tadd Dameron’s “Hot House” is Cole Porter’s “What Is This Thing Called Love?” with the romance surgically removed and something far more astringent put in its place. And Thelonious Monk’s “Evidence” sits on “Just You, Just Me” — a piece of chord borrowing with a joke buried in the title, since “just you, just me” gives you “just us”, which gives you “justice”, which gives you evidence. That’s very much how Monk’s mind worked.
The one that proves the rule
It’s worth knowing that Parker didn’t do this with everything.
“Confirmation” — one of the finest things he wrote, and a tune every jazz musician eventually has to learn — is not a contrafact. Both the melody and the harmony are original. He built the whole thing from nothing.
That matters because it undercuts the lazy version of this story, the one where bebop composers are basically clever thieves working a legal angle. Parker could write changes when he wanted to. He mostly chose not to, because the shared repertoire was doing something useful: it meant five musicians who had never met could count off a tune in a club at two in the morning and be completely aligned within four bars.
Why it still matters
Walk into a jam session tonight, anywhere in the world, and the mechanism is unchanged. Someone calls a rhythm changes tune. Nobody needs sheet music, because everyone already knows the underlying map — they’re just agreeing on which melody to put over it.
That’s the real legacy of the contrafact, and it outlasted the economics that helped produce it. A generation of musicians took the popular songs of their day, kept the bones, threw away the flesh, and built a common language that improvisers still speak eighty years later.
The copyright loophole was the opportunity. What they did with it was the point.
More on the tunes and musicians that built the jazz repertoire in the Jazzfuel archive — or sign up for the Weekend Edition newsletter for a jazz reading list every Saturday.
