The final movement of the fourth of them opens with a descending scale before the folk-song "The Birch Tree" is quoted, while the piece ends in the key of F major.  
The final movement of the fourth of them opens with a descending scale before the folk-song "The Birch Tree" is quoted, while the piece ends in the key of F major.  The popular fifth begins with a theme introduced by the clarinets, while the third movement is a waltz, unusual for this kind of composition.  The last of them is a B minor work which premiered less than a month before the composer's death.  The first three have nicknames, such as "Winter Daydreams" and "Polish."  FTP, name this group of six orchestral works by a Russian composer, the last of which is known as the "Path?ique."
The final movement of the fourth of them opens with a descending scale before the folk-song "The Birch Tree" is quoted, while the piece ends in the key of F major.  
the symphonies of Peter Ilitch Tchaikovsky (accept equivalents)