Original sentence: After World War I, Canadian musicians-composers began to study abroad in numbers, experiment with the compositional techniques of their American and  European colleagues
Edited sentence: Canadian songwriters contributed some of the most famous popular music and jazz "standards" of the 19th century.Following quickly on the gramophone's spread came World War I.The success of the gramophone at the beginning of the 20th century  allowed Canadian songwriters to broaden their potential audiences.The war was the catalyst for the writing and recording of large numbers of Canadian-written popular songs, some of which achieved lasting international commercial success