Emanuel Ax completes the Beethoven piano concertos with The Philadelphia Orchestra, performing Nos. 2 and 3. When it comes to the cadenzas in these concertos, he says, “I always play Beethoven cadenzas. No one wrote that music like he did. It’s a kind of extended improvisation.” Karina Canallakis, a graduate of the Curtis Institute and a rising star on the podium, makes her conducting debut with the orchestra. —L.J.