I asked recently a friend wihich one he considered as the most beautiful melody in classical music.
I was expecting something like the piano line in the adagio assai of Ravel´s Concerto in G, or Bach´s "Erbarme dich", or the 2nd movement of Schubert´s Piano Trio D929, or Verdi´s "Il balen del suo sorriso", or almost anything by Mozart.
Here you have the answer:
During the classical centuries I would not hesitate to give the first place to the ”song theme” of Borodin’s Polovetzian dances from “Prince Igor”.
But there are strong rivals. One that most of us may be inclined to overlook is “Virgine Bella” by Guillaume Dufay”, 15th century, text by Petrarca.
Many songs by Schubert could be added, and so could many songs by the Danish composers C. E. F. Weyse and Carl Nielsen.
But by Schubert I would also mention the second theme (first time played in F major) of the second movement of his great C major symphony.
Or the beginning of the second movement of Cesar Franck’s symphony.
Maybe also the first theme of Bartok’s second violin concerto.
Near the end of the first act of Paul Dukas’ opera “Ariane et Barbe-Bleu” there is a highly melodic choir which starts in e minor.
Olivier Messiaen had an extraordinary capacity for creating melodies, and many would agree that during the 20th century he has no real rival.
But around 1950 a number of 12-tone composers who felt they had exhausted their own framework became students of Messiaen in the hope that he could help them. In actual fact Messiaen was much influenced by them, and most of what he wrote after that time had a strong ingredient of point music. But point music is hardly suitable for creating melodies. So Messiaen ceased to use or develop one of his greatest talents.
Examples of his best melodies:
“La nativité du Seigneur” (The Birth of Our Lord),
second movement, second theme. When the second them is introduced it will remain until the end of the movement. This is possibly the longest section Messiaen has composed in the key with 9 tones.
Fourth movement, the second theme. It is exclusively accompanied by long unmoving simple harmonies, many of them just major or minor triads.