Drums, cymbals, xylophones, triangles in fact anything that has to be hit in order to make a sound is included in the percussion section.
The timpani are tuned drums, in other words they play particular notes, and they are the most frequently used percussion instruments. They really make up a separate section of the orchestra all on their own. Composers tend to divide their writing for the timpani into two main types: being melodic instruments, picking out the important bass notes of the music (either gently or loudly) and being percussive instruments providing shock interruptions or rolls which form small ripples or can swell into a massive waves of sound sweeping all before them....[more]
The timpani are tuned drums, in other words they play particular notes, and they are the most frequently used percussion instruments. They really make up a separate section of the orchestra all on their own. Composers tend to divide their writing for the timpani into two main types: being melodic instruments, picking out the important bass notes of the music (either gently or loudly) and being percussive instruments providing shock interruptions or rolls which form small ripples or can swell into a massive waves of sound sweeping all before them....[more]
Listen to some percussion
Listen to these audio clips to hear percussion sounds in the Philharmonia Orchestra:
clip 1 -
A timpani solo - The Planets: Uranus by Holst.
clip 2 -
Dampened tam-tam, joined by guiro: The Rite of Spring by Stravinsky.
clip 3 -
Tiny antique cymbals create magic in this passage from Prélude a l'après-midi d'un faune by Debussy.