The brass section is the most powerful section in the orchestra. Trumpets, French horns, trombones, euphoniums, baritones and tubas find their place in this section. The trombone is part of the brass section because of the method in which it produces its sound and the material used in construction. Brass instruments all make use of a mouthpiece that can be made of steel, silver, gold or even plastic. Additionally, the actual construction of the instrument uses a large portion of brass.
Within the brass section there is an additional sub-type in which low-brass and high-brass are divided. The low brass consists of trombones, tubas, euphoniums and baritones. The high brass usually includes the French horns, trumpets and cornets. Low-brass instruments play in the lowest bass clef range of the instrument and high-brass plays in the treble clef higher range. The distinction is important since many times the composer will divide the brass section into solo groups.
The exact placement of the trombone section is almost uniformly the same in all orchestras. From the viewpoint of the audience member, the trombones sit on risers at the back right of the ensemble. Immediately in front of them will be the tubas and baritones if they are used and trumpets will sit to the left of them. This seating arrangement allows for the best acoustics of the trombone section. Placing this section to close to the front would cause them to be too overpowering. Placing them in the middle would create an unbalanced sound in which the trumpets sound weak and thin.
In some rare occasions, the trombones won't be seen on stage at all or half of them will be removed from the orchestra and half will stay. When this happens it is usually so that a section of trombones play at a separate location within the hall. Many concert halls have eaves, which the trombonists and other brass members perform an antiphonal melody displaced from the orchestra. This effective placement creates the illusion that trombones are playing from a distance.