Simplify the following text for a Grade 9 native English-speaking person.
Original: In addition to bringing the Orchestra to new virtuosic heights , the highlights of his tenure included a series of free Memorial Day Concerts at the Cathedral of St. John the Divine and annual concert tours abroad that included the orchestra 's first trip to mainland China .
Simplified: During his time he included a series of free Memorial Day Concerts at the Cathedral of St. John the Divine and annual concert tours abroad that included the orchestra 's first trip to mainland China .