It's vintage Tchaikovsky. Symphony No. 1 comes with a ton of judgment followed by a nervous breakdown mixed with a dozen tragically beautiful melodies and a dash of a Russian folk tune.
Tchaikovsky waited until he was a professor at the Russian Musical Society (which would become the Moscow Conservatory) to start writing his first symphony in 1866.
He desperately wanted to hear it played at a Russian Musical Society concert, but needed approval of his colleagues, Anton Rubinstein and Nikolai Zaremba.
He spent weeks upon weeks of work-filled, sleepless nights writing the symphony. It nearly killed him, and it contributed to a nervous breakdown in the midst of the composition.
Following his recovery, Tchaikovsky showed it to Rubinstein and Zaremba. As was too often the case, they hated it, and forced Tchaikovsky to make some big changes.
What did they hate about it, though? They disliked the structure of the piece, and they thought it was too melodic. Too melodic!
Rubinstein and Zaremba were old-school (1866, after all, is still considered early in the Romantic era), and Tchaikovsky only listened to some of their advice, thankfully.
The melodies in this symphony are as gorgeous as you'd expect with Tchaikovsky. Not all of the material is original to the symphony; he borrowed music from one of his overtures (The Storm, published posthumously) and a Piano Sonata (in C-sharp minor).
Tchaikovsky gave the symphony a subtitle, "Winter Dreams", and the first two movements also have titles. Oddly, the final two movements only have their tempo markings for names no subtitles.