symphonies n tchaikovsky wiki
https://en.wikipedia.org/wiki/Symphonies_by_Pyotr_Ilyich_Tchaikovsky The fruit of Liszt's labors was what he eventually termed symphonic poems. In them, he used two alternatives to sonata form. Beethoven had used the first of these, cyclic form , to link separate movements thematically with one another. Liszt took this process one step further by combining themes into a single-movement cyclic structure.[58] The second alternative, thematic transformation, originated with Haydn and Mozart.[59] This process worked in a similar manner as variation but instead of a theme being changed into a related or subsidiary version of the main one, it becomes transformed into a related but separate, independent theme Keller offers the second theme in the first movement of the Fourth Symphony as an example of how this process works. In sonata form, he writes, the first subject enters in the tonic and the second subject follows in a contrasting but related key harmonically. Tension occurs when...
