Franz Schubert, born in 1797, was very prolific in his short life of 31 years. He never composed a Samba but was known for the attractive melodies and harmonies in every piece he wrote.  Schubert's compositions often contain sudden, rather than carefully modulated changes of key.  He would commonly keep the top note in one bar constant while in the following bar the notes underneath change to a remote key. Such an unexpected change may sound pleasant or unpleasant. What do you think? This effect occurs at bars 16 and 17 and later on in a slightly different context.