Imagine what life would be like if lived, in May Sarton’s lovely phrase, with “joy instead of will.” That is what Beethoven imagined, and invited humanity to imagine, two centuries ago in the choral finale of his ninth and final symphony, known as “Ode to Joy” — an epochal hymn of the possible, half a lifetime in the making.

In the spring of 2012, the Spanish city of Sabadell set out to celebrate the 130th anniversary of its founding with a most unusual, electrifying, and touchingly human rendition of Beethoven’s masterpiece, performed by a flashmob of 100 musicians from the Vallès Symphony Orchestra, the Lieder, Amics de l’Òpera and Coral Belles Arts choirs. Watching the townspeople — children with kites, elders with walkers, couples holding hands — gather to savor the unbidden music in a succession of confusion, delight, and ecstasy is the stuff of goosebumps: living proof that “music so readily transports us from the present to the past, or from what is actual to what is possible.”

Couple with the remarkable story of the making of “Ode to Joy,” then revisit the neurophysiology of enchantment and how music casts its spell on us.