Complex sentence: Harry carried notebooks with him, collecting information about the local groups, once writing to "The Daily Mail", that "Liverpool is like New Orleans at the turn of the century, but with rock" n "roll instead of jazz".
Split into simpler sentences: Harry carried notebooks with him, collecting information about the local groups. Harry once wrote to "The Daily Mail", saying that "Liverpool is like New Orleans at the turn of the century, but with rock" n "roll instead of jazz".