Paul Elie, author of Reinventing Bach, is spelling out a wonderfully homey theory about the greatest musician who ever lived. And jazz pianist Donal Fox is demonstrating the idea in real time, on my piano. We’re blessed to share it, in praise and thanksgiving, as a Christmas offering from Open Source.

Why, we ask, does Johann Sebastian Bach (1685 – 1750), “the Leonardo of sound,” sit virtually alone and god-like, in so many testimonies, at the peak of all artistic creation? The great clarification here is that Bach left not just a multitude of masterworks; but further that in his notebooks and albums of instruction, in exercises for his children and minimal “inventions” for keyboard students ever after, he made clear he was giving the world a “source code” of music. He composed, in effect, bone-marrow or stem-cell music, ready to be extended into new shapes and sounds, new limbs and organs, new life and insight and delight until the last trumpet sounds.

Much of Paul Elie’s marvelous book recounts the Age of Recording, starting in the 1930s, and the ways it accelerated and compounded the meanings of “reinventing Bach.” Albert Schweitzer made an organ thunderbolt of Bach’s Toccata and Fugue in D Minor to wake a dying Europe in 1935. In Hollywood the next year, Leopold Stokowski transcribed the same music from organ to full-orchestra for the opening theme of Walt Disney’s Fantasia. Pablo Casals’ recording of the then unknown Cello Suites in 1939 was called “a Catalan cry of the heart” at the end of the Spanish Civil War. Casals declined to play the Bach Suites in his native Spain — or even in the Kennedy White House — as long as Generalissimo Franco lived and ruled. In much the same spirit the pianist Leon Fleisher decided he could not play “Jesu Joy of Man’s Desiring” or “Sheep May Safely Graze” in George W. Bush’s White House, in fact wouldn’t perform at all. Yo-Yo Ma’s performance from the Cello Suites at Steve Jobs’ funeral reminded everybody of Jobs’ legendary judgment that those pieces and Ma’s playing of them made “the best argument I’ve ever heard for the existence of God, because I don’t really believe a human alone can do this.”

From the Swingle Singers‘ scat versions of Bach instrumental pieces in 1963, more recently Bobby McFerrin’s singing the “Air on a G String,” Savion Glover‘s tap dancing to Bach and the infinite mash-up possbilities, Paul Elie looks forward to almost endless extensions on his catalog of Bach reinventions. And still isn’t the heart of the story in the beginning? That is, in Bach’s own handwritten notebook for his nine-year-old son William Friedemann? It held musical sketches of melodies and implied harmonies, basic exercises in rhythm and counterpoint; but many pages were left blank, as Elie writes, “to be filled with pieces that father and son, teacher and student, would compose together.” The exercise was to discipline fingers and ears, mind and heart, to cope with tension and dissonance, design and surprise, inversions of phrases, the pulse of a bass line, the tempos of life. What Bach is still offering us, as Craig Smith used to say, is “a way to live.”