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