While Mahler famously opined that a symphony should “contain the entire world,” it occurs to us that he didn’t specify exactly what size that world ought to be! In 2007, the German conductor Klaus Simon transcribed the great sonic architect’s Symphony No. 4 — originally requiring 60 or more musicians — for a small chamber orchestra, creating a more intimate and sensitive perspective on this towering work. The HSO warmly welcomes soprano Kristine Biller as soloist in this afternoon’s performance.