The composer and pianist Timo Andres’s take on the “Coronation” (otherwise known as the Piano Concerto No. 26 in D) felt necessary — not a lark but a surprisingly moving dazzler.
Mr. Andres’s version, first performed in 2010, gains legitimacy from the fact that the original score leaves out large swaths of the left-hand half of the piano part. Mozart — both the work’s composer and performer — would simply have known what to play.