The strings section is made up of violins, violas, double basses, cellos, a harp and, occasionally, guitars. Violinists are divided into two sections, known as first violin and second violin. All of the stringed instruments are forwardly placed in the symphony seating arrangement, closest to the conductor. The violins are placed together on one side and the viola, cellos and double bases placed on the other. The harp is usually placed on the same side as the violins, just behind the first violin section. The guitar, when used, is usually set off to the side for most of the symphonic piece and moved to the front of the stage for any guitar solos.
Instruments found in the woodwind section of a symphony orchestra include bassoons, clarinets, flutes, oboes, recorders and saxophones. In general, the woodwind section is placed in the middle of the orchestra, seated directly behind the second violins and the violas. Depending on whether it is a chamber orchestra or a symphony orchestra, there may be only one or two of each type of woodwind instrument being played, although there are usually at least two saxophones present -- a tenor sax and an alto sax.
The brass section of a symphony orchestra is made up of trombones, trumpets, French horns, cornets and tubas. They can generally be located behind the cellos and double basses, off to one side, next to the woodwind section. Similar to the woodwind section, there may be as few as one of each instrument in the orchestra, depending on its size.
Percussion instruments include drums, cymbals, the tambourine, the triangle and the piano. The percussion seating area in a symphony orchestra is generally in the back, with the exception of the piano. Depending on the piece being played, the piano can be placed in the center of the orchestra, next to the woodwind section, or off to the side -- next to the harp. On rare occasions, the piano will be wheeled to the front, next to the conductor, for piano-specific pieces of music.
Sometimes vocalists are included to sing with the orchestra for a symphony piece. For example, if the orchestra is playing works from an opera, a mezzo soprano or a tenor may accompany the orchestra on some or all of the works played. A vocalist takes center stage, just off to one side of the conductor.