Hollywood Backup Singers is an EastWest vocal library, and its role in a production is a specific one: backing vocal parts are not simply quieter lead vocals. They differ in range — often sitting above or below the lead rather than in the same register — in performance — stacked and locked rather than soloistically phrased — and in number, since a background stack may be three or five voices deep. A library built for that job supplies layered ensemble performances, which is what distinguishes it from the developer's solo and choral titles. Content of this kind typically provides stacked vocals in several voice configurations, with sustained notes, short stabs, and performed phrases, plus the vowels and syllables that background parts actually use — often wordless or syllable-based rather than lyrics. EastWest's vocal range is unusually broad, with Hollywood Choirs supplying a blockbuster female and male choir with unprecedented dynamics, Voices of Opera offering a 40 GB collection of 229 multi-sampled vocal instruments featuring soprano Larisa Martinez and tenor Carlton Moe, and Voices of Soul and Voices of the Empire covering further styles — so Hollywood Backup Singers fills the contemporary pop and R&B backing role in that catalogue. It includes "Opus" as a sample player, running as standalone or plug-in in AAX Native, AU, VST2, and VST3 on Mac and Windows, and is available as a perpetual licence or via ComposerCloud+. Requirements for Opus libraries are macOS 10.15 or higher (64-bit) or Windows 10 or higher (64-bit with an ASIO sound driver), with a quad-core CPU (octa-core recommended) at 2.7 GHz or higher, 16 GB RAM (32 GB or more recommended), and an SSD hard drive (SATA or PCIe). It suits pop, soul, R&B, gospel, hip hop, and cinematic production, and is equally useful for advertising and trailer work where a vocal stack is needed without a session. #HollywoodBackupSingers #EastWest #VocalLibrary #BackingVocals #BackgroundVocals #VocalStacks #Pop #Soul #RandB #Gospel #HipHop #FilmScore #Television #TrailerMusic #Opus #ComposerCloud #SoundDesign #MusicProduction #AAX #AU #VST2 #VST3 #Standalone #LogicPro #Cubase #ProTools #Reaper