The discovery in St. Petersburg of a full libretto from the second performance in 1744 of Bach’s missing Passion set the sleuths to work. And here’s the result: Following this revised edition, a full-length creation emerges, the work of Jordi Savall based on research by German harpsichordist/musicologist Alexander Grychtolik. The music, all by Bach, has been borrowed from a host of different places, including the two surviving Passions and some cantatas. Savall’s lively musical instincts and his flair not just for reconstruction, but also for imbuing it with vigorous life make this mandatory listening, especially given the quality of the performance.