In 1905, Widor and Schweitzer were among the six musicians who founded the Paris Bach Society, a choir dedicated to performing J. S. Bach's music, for whose concerts Schweitzer took the organ part regularly until 1913. He was also appointed organist for the Bach Concerts of the Orféo Català at Barcelona, Spain, and often travelled there for that purpose. He and Widor collaborated on a new edition of Bach's organ works, with detailed analysis of each work in three languages (English, French, German). Schweitzer, who insisted that the score should show Bach's notation with no additional markings, wrote the commentaries for the Preludes and Fugues, and Widor those for the Sonatas and Concertos: six volumes were published in 1912–14. Three more, to contain the Chorale Preludes with Schweitzer's analyses, were to be worked on in Africa, but these were never completed, perhaps because for him they were inseparable from his evolving theological thought.
In 1905, Widor and Schweitzer were among the six musicians who founded the Paris Bach Society, a choir dedicated to performing J. S. Bach's music, for whose concerts Schweitzer took the organ part regularly until 1913. He was also appointed organist for the Bach Concerts of the Orféo Català at Barcelona, Spain, and often travelled there for that purpose. He and Widor collaborated on a new edition of Bach's organ works, with detailed analysis of each work in three languages (English, French, German). Schweitzer, who insisted that the score! should show Bach's notation with no additional markings, wrote the commentaries for the Preludes and Fugues, and Widor those for the Sonatas and Concertos: six volumes were publ?ished in 1912–14. Three more, to contain the Chorale Preludes with Schweitzer's analyses, were to be worked on in Africa, but these were never completed, perhaps because for him they were inseparable from his evolving theological thought.