Complex sentence: After their first performance in Kiev in 2012, a Queen + Adam Lambert mini-tour followed with dates in Moscow, Wrocław, and London, and in September 2013 they appeared as a headliner at the iHeartRadio Music Festival in Las Vegas in September 2013.
Split into simpler sentences: After their first performance in Kiev in 2012, a Queen + Adam Lambert mini-tour followed with dates in Moscow, Wrocław, and London. In September 2013 they appeared as a headliner at the iHeartRadio Music Festival in Las Vegas in September 2013.