(Answer would typically be an essay, but here are two paragraphs.)
Shostakovich’s 5th Symphony uses a variety of timbres to enhance the conflicting emotions of despair and triumph in the melodic and harmonic ideas. For the more triumphant melodies, reflecting the domination of the Soviet army, Shostakovich uses the harsh brass timbre over percussion, such as at figure 27 in movement 1. The trumpets play fortissimo, making the sound aggressive, whilst the timpani plays tonic to dominant crotchet beats, mimicking the left-right movement of a march. Similarly, the snare plays an unrelenting motor rhythm, taken from the strings at figure 25, creating the sounds of a marching band whilst also creating momentum.
In contrast, at figure 96 at the end of movement 3, Shostakovich uses instrumental colour to portray the sorrow of the Soviet people. The celeste has an eerie timbre, suggesting fear and danger, whilst the use of harmonics on the harp creates a light, barely perceptible sound. Joined with the slow, falling melody of the D motif, Shostakovich has created a tearful, melancholy feeling, which is possible a reflection on the death of his friend, a possible inspiration for the movement. Accompanying the melody is the first violin playing a tremolo on a high F#. The tremolo itself creates a fragile, anxious feeling in the audience, but partnered with the high note, it sounds as if it is close of breaking, reflecting the highly emotional mood.