Returning to the Prague Summer Nights: Young Artists Music Festival for his fourth consecutive season, for the first time ever, Walter Seyfarth —Berliner Philharmoniker clarinetist, since 1985 — will perform Mozart ‘sClarinet Concerto in A Major at the historic Estates Theatre …the very venue Viennese clarinetist Anton Stadler premiered the piece on October 16, 1791.