The beguiling and brilliant keyboard flourishes of Grieg’s only piano concerto are executed by the flawless Joyce Yang in her return engagement with the BPO. The lighthearted musical imagery is extended with the Classical Symphony of Prokofiev, an appealing nod to Haydn and the 18^th century, which also inspired Stravinsky’s witty Pulcinella Suite, originally scored as a one-act opera with sets designed by Picasso.