section_path: Musical style/Structure and lyrics
section_name: Structure and lyrics
paragraph_text: Structure and lyrics
  
  Bach devoted more attention than his contemporaries to the structure of his compositions. This can be seen in minor adjustments he made when adapting someone else's composition, such as his earliest version of the "Keiser" St Mark Passion, where he enhances scene transitions, and in the architecture of his own compositions such as his Magnificat and Leipzig Passions. In the last years of his life, Bach revised several of his prior compositions. Often, recasting such previously composed music in an enhanced structure was the most visible change, as in the Mass in B minor. Bach's known preoccupation with structure led (peaking around the 1970s) to various numerological analyses of his compositions, although many such over-interpretations were later rejected, especially when wandering off into symbolism-ridden hermeneutics.
  
  The librettos, or lyrics, of his vocal compositions played an essential role for Bach. He sought collaboration with various text authors for his cantatas and major vocal compositions, possibly writing or adapting such texts himself to make them fit the structure of the composition he was designing when he could not rely on the talents of other text authors. His collaboration with Picander for the St Matthew Passion libretto is best known. However, there was a similar process in achieving a multi-layered structure for his St John Passion libretto a few years earlier.