An orchestra was a group of musicians that played together. Orchestral music was one type of music produced by many cultures. (VOY: "Virtuoso")
In 2365, Geordi La Forge (incorrectly) guessed that the setting of Worf's second Rite of Ascension involved a "twenty piece orchestra, magnificent ballroom, everybody in formal wear." (TNG: "The Icarus Factor")
Later that uear, Q compared the scenario he had placed Captain Jean-Luc Picard and USS Enterprise-D's crew in to a dance; "The hall is rented, the orchestra engaged. It's now time to see if you can dance." (TNG: "Q Who")
In 2368, Jean-Luc Picard was surprised to learn that Kamala had taken music lessons as a child and knew how to play all the instruments of the orchestra, including Valtese horns. (TNG: "The Perfect Mate")
In 2372, upon discovering Harry Kim attempting to practice his clarinet, Tom Paris questioned his dedication to practice, sarcastically asking if USS Voyager was going to rendezvous with the Delta Quadrant Symphony Orchestra. Kim explained that he and Susan Nicoletti were working on a new orchestral holoprogram. (VOY: "The Thaw")
In 2373, The Doctor explained to a hologram of Giuseppina Pentangeli that since he had programmed the orchestral playback for O, soave fanciulla, she would take her tempo from him. (VOY: "The Swarm")
In 2377, noticing Fantome's positive reaction to his humming an aria from Rigoletto, The Doctor had the computer play the full orchestral version of the song. (VOY: "The Void")
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