Music developed and modernized unstoppably in the tense environment of the 19th century. Parallel to the industrial and technical revolution of the era, many composers broke away from the firmly chiseled rules of music theory and took ever greater liberties. Singer Pur traces this arc of tension here. The composers of the selected pieces were likely very different in their attitudes toward faith and spirituality. Anton Bruckner, who is said to have had an almost childishly pure faith, probably struggled less with his attitude toward God than Franz Liszt or Max Reger, for example.