Sting deserved a lot of compliments for the promotion of interdisciplinary understanding when he arranged for the “prima ballerina assoluta” Alessandra Ferri to dance while he played a guitar transposition of the Prelude from Bach’s Cello Suite No 1 in G major, with choreography by Heinz Spoerli and understandably lingering direction by the dancer’s husband, Fabrizio Ferri.