Beethoven's Fifth Symphony is probably the best known musical composition of all time. Knowing the instruments involved can help us secure what it means to have "standard orchestration." As you will see from the previous answers above, it is a quite standard orchestration for Beethoven's Fifth Symphony. (Keep in mind that "Beethoven's Fifth Symphony" is it's familiar title. The "actual" or "original" title is Symphony No. 5 in C Minor, Opus 67.
What is standard orchestration: In this case, let's take each class of instruments separately. In regards to woodwinds, there are two bassoons, two clarinets (B flat & C), one double bassoon, two flutes, and one piccolo. In regards to brass, there are three trombones (alto, tenor, and bass), two french horns (in E flat & C), and two trumpets. In regards to strings, they run the full range and have different numbers of each according to the production; however, generally we are talking about violin, viola, cello, and bass. For percussion, timpani is used (all drums from G through C). Also, please keep in mind that the conductor can add and subtract instruments according to his or her individual style.
It is also important to note that the fourth movement of Symphony No. 5 in C Minor, Opus 67 stands out from the others due to the addition of the following instruments: double bassoon, piccolo, and trombone. All of the other instruments are used in all of the other movements.
In conclusion, it is interesting to note that Beethoven used the Key of C for his Fifth Symphony (often said to be the key of "stormy, heroic tonality") and that there is "single motif that unifies the entire work" namely those famous "four notes" that we all know so very well.
Beethoven's Fifth Symphony, officially entitled Symphony No. 5 in C Minor, Opus 67, uses a fairly standard combination of instruments in its original orchestration. The arrangement was composed and scored for performance by two bassoons, two clarinets - one in B flat and one in C, contrabassoon, two flutes, two horns - one in E flat and one in C, timpani - using G through C, three trombones - alto, tenor, and bass, two trumpets, and a full range of strings (violin, viola, cello, bass viol).
The contrabassoon, piccolo, and trombones play only in the fourth movement. In particular, the need for horns playing in different keys arises from the fact that there were no horns with valves allowing for easy transitions from their natural key to another key. Beethoven's solution was to call for the availability of instruments in both of the needed ranges.
The first three movements of Beethoven's Symphony no. 5 use two each of flutes, oboes, clarinets, bassoons, horns, and trumpets; two timpani, tuned to the pitches C and G; and groups of violins (divided into first violins and second violins, which play different parts), violas, cellos, and double basses. This is a very typical-size orchestra for music of the time (the symphony was first performed in 1808).
The fourth and final movement adds a piccolo, a contrabassoon, and three trombones. At the time, these instruments were used rarely in symphonies, though they were found more often in operas. Beethoven, therefore, was breaking new ground; his use of these additional instruments made possible a wider range of color, grandeur, and brilliance, and the larger-the-usual orchestra is one of the factors that makes this final movement one of his most stirring pieces of music.
Two Flutes, a Piccolo, Two Oboes, Two Clarinets, Two Horns, Two Trumpets, Alto Trombone, Tenor Trombone, Bass Trombone, Timpani, Violin 1, Violin 2, Violas, Cellos, Basses