Throughout his life, Pierre Boulez was famously allergic to finality. Many of his works stayed in a state of flux for decades, evolving with each performance or publication. But few pieces remained as unfinished—and as elusive—as his only string quartet, Livre pour Quatuor. Originally conceived in 1948, alongside his Second Piano Sonata and Le Soleil des Eaux, the work remained incomplete for nearly 70 years.

For decades, only five of the six planned movements were available to performers and audiences. It wasn’t until 2017—two years after Boulez’s death—that composer Philippe Manoury reconstructed the missing fourth movement, finally bringing Livre to completion. Boulez’s inspiration for the quartet was anything but traditional. He took the late quartets of Beethoven and Berg’s Lyric Suite as points of departure—not for imitation, but to push back against. What emerged was a bold, modular work steeped in total serialism, influenced by Webern and Messiaen, with a structure inspired by Stéphane Mallarmé’s Livre—a book designed to be read in any sequence. Similarly, Boulez intended this piece to be played in various orders, allowing performers to shape its form.

Enter Quatuor Diotima. Having worked with Boulez during the last decade of his life, they bring deep insight and clarity to this complex score. Their previous recording captured the earlier five-movement version, but this new release—featuring the complete six-movement work for the first time—feels definitive. The performance balances Boulez’s extremes with precision and flair: icy stillness gives way to manic energy, sparse textures bloom into dazzling density. It’s cerebral music, yes, but also startlingly vivid. Livre pour Quatuor may still be one of Boulez’s most demanding works, but in the hands of Diotima, it finally sounds whole—and alive. A landmark release for fans of modern chamber music.