Complex sentence: For the 50th Anniversary Jubilee Concert, Madam Tan Lin introduced the Catholic High School Symphony Orchestra, which was formed ad hoc, comprising members from the brass band, Oriental Music Orchestra and other string instrument players selected from the student body.
Split into simpler sentences: For the 50th Anniversary Jubilee Concert, Madam Tan Lin introduced the Catholic High School Symphony Orchestra. The orchestra consisting of members from the brass band, Oriental Music Orchestra and other string instrument players were selected from the student body.