Complex sentence: At the age of 21, Black was discovered by Warner/Chappel Publishing who immediately signed her and shortly after that she was courted by Universal Music Canada where she was offered a deal to help propel her career.
Split into simpler sentences: At the age of 21, Black was discovered by Warner/Chappel Publishing who immediately signed her. Shortly after, she was courted by Universal Music Canada where she was offered a deal to help propel her career.