These are two movements from two of the best kown Beethoven piano sonatas, the Adagio from op.13, also known as 'Pathetique', and the Allegretto from op.27 no.2, the 'Moonlight sonata'.
Both movements are not in the original key. Op.13 was transposed from A flat major to G major (D major in horn pitch), and op. 27 no.2 from D flat major to E flat major (B flat major in horn pitch). Also, the broken chord accompaniment figures were modified, and octave displacements to stay within an acceptable range abound.
This is one of many excellent Pottag arrangements for horn ensemble, and a sure crows pleaser.