I'm busy with the first symphony of Peter I. Tchaikovsky. In movement 1 the time signature is 2/4. Can someone explain the choice of putting 2/4 instead of 4/4. If it goes with the feel I don't feel 2/4 more then 4/4? Or there are other parameters that made him choose 2/4.
In general a (classical) 4/4 signature emphasises the first and third beat, with the first beat being emphasised slightly (but noticeable) more than the third beat.
In a 2/4 signature, the first beat is emphasised in each bar to give it a march feel. Think 1 2 1 2.
If one was to rewrite a 2/4 as a 4/4 then one would lose the equal emphasis on every first beat in the bar, replacing alternate 1's with a slightly less emphasised third beat.