Simplify the following text for a Grade 10 native English-speaking person.
Original: This was followed by his becoming the Organist at Gainsborough Parish Church in 1933 , and then a move to Leamington Spa to be the Organist of Holy Trinity church in 1939 .
Simplified: In 1933 he became Organist at Gainsborough Parish Church , then went to Leamington Spa as Organist of Holy Trinity church in 1939 .