Complex sentence: On August 31,2012, during a show in Argentina Farrar filled-in for Mickey Madden on the bass guitar for the very first time he subsequently filled-in for Madden on the next few shows of the tour.
Split into simpler sentences: On August 31,2012-during a show in Argentina-Farrar filled-in for Mickey Madden on the bass guitar for the very first time. He subsequently filled-in for Madden on the next few shows of the tour.