Complex sentence: In September 2001 the band appeared at Madison Square Garden alongside Luther Vandross and Usher singing Michael Jackson's hit song "Man in the Mirror", the performance was part of show to celebrate Michael Jackson's 30 years as a solo artist.
Split into simpler sentences: In September 2001 the band appeared at Madison Square Garden alongside Luther Vandross and Usher singing Michael Jackson's hit song "Man in the Mirror". The performance was part of a show to celebrate Michael Jackson's 30 years as a solo artist.