Alexander Gadjiev, a young and already highly acclaimed pianist from Gorizia, accompanied by the ORT and conducted by the Israeli conductor Daniel Cohen, tackles Sergei Prokofiev’s Concerto No. 3, a score of biting modernism that demands absolute technical precision, Beethoven’s Leonore Overture No. 3 and Schubert’s Unfinished Symphony, in the completed version that musicologist Brian Newbould has recently created.