Beethoven Piano Concertos Nos. 2 & 4: Leif Ove Andsnes and the Mahler Chamber Orchestra
Beethoven wrote 5 piano concertos. The (published as the) 2nd Piano Concerto was written before the first Piano Concerto. The Fourth Piano Concerto "threw it's audiences a curve (ball)" by starting with the solo piano, which is not a characteristic start to a 'piano concerto'.