Trailer-type mobile stages are pulled by large, heavy-duty pickup trucks or semi-trucks. The stage is folded when it arrives at a concert site. Laborers manually unfold the trailer; the platform is flat. Trailer stages do not have overhead covers for the public address system and lighting fixtures. However, the stage production company that owns the trailer stage sometimes builds a temporary roof over the stage to accommodate sound and lighting. The advantage of these stages is that they are already hooked up to a vehicle. The disadvantage is that trailer stages require more manual laborers to set up than do hydraulic stages.
Rather than manual labor, hydraulic stages use hydraulics technology to set up their units. This is the type of mobile stage more frequently seen at large indoor or outdoor concerts. Most hydraulic stages come equipped with an overhead cover, which a stage production company uses for light rigging and sound system equipment. Although they tend to be more expensive to rent than trailer stages, hydraulic stages do not require as much labor or time to build and set up. Many hydraulic stages fold into an enclosed trailer for traveling.
Smaller acoustic or theatrical performances employ 16-ft.-by-16-ft. stages. Stages of this size are usually trailer stages. Hydraulic stages are generally preferable for larger events such as rock concerts with four- to five-member bands, dance concerts and choir ensembles. Larger stage sizes include 32-, 36- and 40-ft.-wide. Larger stages usually have depth measurements ranging from 20 ft. to 25 ft.; some of the largest stages have 40-ft. depths. Most overhead covers for large hydraulic stages hang 17 ft. to 20 ft. over the stage's platform.
Stage production companies exist in large urban areas with active music scenes, including Los Angeles; Austin, Texas; New York City; Chicago; and Nashville, Tennessee. Famous rock 'n' roll bands and entertainment festivals usually hire a stage production company to travel with them for the duration of a tour to set up the stage. Some well-known stage production companies are Brown United, which has set up stages for music artists such as Eminem, KISS and Billy Joel; Roadway Productions, based in Austin, Texas; and Center Staging, a New Orleans-based mobile stage company. Center Staging is responsible for erecting the concert stages for the city's Mardi Gras celebration.