Hollywood Studio Symphony

The Hollywood Studio Symphony is the credited name of the symphony orchestra behind many major soundtracks, including The Chronicles of Narnia: The Lion, the Witch and the Wardrobe, Sucker Punch, Jurassic Park 3, Last Samurai, Pirates of the Caribbean, We Are Marshall, Spider-Man 2,  Lost and The Bourne Supremacy. Although the name "Hollywood Studio Symphony" may lead listeners to think that it is a conventional symphony orchestra like the London Symphony Orchestra, the actual members of the ensemble are session musicians contracted individually and differ from soundtrack to soundtrack.

Note, the Hollywood Studio Symphony bears no relation to the similarly named Hollywood Symphony Orchestra, which is more akin to a traditional orchestra with a set roster.

Background
Often in soundtracks, the individual members of the orchestra that performs the actual score are not credited (with some exceptions being the "orchestra leader" or concertmaster). Usually, only the "orchestra contractor" is credited.

The use of the "Hollywood Studio Symphony" name is part of a 2002 contract negotiated between the American Federation of Musicians and the Alliance of Motion Picture and Television Producers to provide an incentive for soundtracks to be recorded with Los Angeles musicians instead of foreign musicians and recording venues (often in London and Prague) who were cheaper. In the new contract, the AFM musicians agreed to lower their record rates in exchange for individual credits to all the musicians that perform the score as well as recognition for the local community venture. Thus, the "Hollywood Studio Symphony" name is given to the entire ensemble in addition to the individual musician credits as a way to brand the LA effort.