There's a variety of them, usually a large amount of strings (Violins, Cellos, Bass, guitars). There's also drums to keep tempo. Occasionally you'll get a xylophone. There's always some brass as well (Trumpets, trombones, french horns, saxophones). Not to forget other instruments like woodwinds(flutes, clarinets). Then there's always a chance of instruments that aren't conventional (pots and pans, kazoos)
Some instruments in the orchestra are violins, violas, cellos, basses, flutes, clarinets, french horns, trumpets,trombones, tubas, cymbals, snare drums, bass drums and timpani.
