Original sentence: 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, which  first started  publishing Jukebox charts in 1936
Edited sentence: 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, which  started  publishing Jukebox charts in 1936