Complex sentence: His association with singer shadia was milestone in the history of Egyptian music for thir songs have become classic songs of romance in Egypt, in addition of songs for Abdel Halim Hafez, which served as a special part of Halim experience.
Split into simpler sentences: His association with singer shadia was a milestone in the history of Egyptian music for their songs have become classic songs of romance in Egypt. In addition songs for Abdel Halim Hafez, which served as a special part of Halim experience.