There are famous pieces for piano that also exist in orchestrated versions. The prime examples are probably Grieg's Peer Gynt Suites and Moussorgsky's Pictures at an Exhibition. The orchestrated versions are much more popular than than (solo) piano versions.Question #1: Why is this so? Perhaps, because the orchestra is just so much more versatile an instrument than the piano and therefore more suitable and powerful to convey musical messages. Any thoughts?Question #2: Is it possible to orchestrate any piano piece and come up with a "better" version? What would "better" mean? Would it mean "more popular" or "more powerful", "more convincing"? There are wonderful orchestrated versions of Satie's Gymnopedies that are very touching, in fact more touching than the original versions.Question #3: What can the piano do that an orchestra could not?I wonder how Beethoven sonatas would sound if properly orchestrated...
Answer to #1: No, because the specific pieces lend themselves to orchestration, and the orchestrators - Ravel, etc. - were very good.
Answer to question #2: No. Can you imagine the Liszt Bminor sonata for orchestra. Could you you imagine Chopin's F minor Ballade for orchestra? Some pieces can be orchestrated, some can't very successfully.
Answer to question #2: No. Can you imagine the Liszt Bminor sonata for orchestra?