Original sentence: Canadian songwriters contributed some of the most famous popular music and jazz "standards" of the 19th century.Prior to the explosion of rock and roll in the 1950s, Canada produced a number of notable international recording artists who appeared on the Billboards record sales chart called Hit parade first published in  1936
Edited sentence: Canada has produced a number of notable international recording artists who appeared on the Billboards record sales chart called Hit parade first published in  1936.The 1920s saw Canada's first radio stations, this  allowed  Canadian songwriters to  contributed some of the most famous popular music of the early 20th century