FORT WORTH — You can’t accuse the Fort Worth Symphony Orchestra of thinking small this weekend. The program lineup includes one medium-sized work that was probably unknown to anyone in Friday night’s audience and two large-scale masterpieces — Brahms’ Piano Concerto No. 2 and Sibelius’ Symphony No. 5.The unknown work was Gyorgy Ligeti’s Romanian Concerto. The name of that composer might have made a few people nervous, because Ligeti, who died in 2006, was best known in avant-garde circles. The one place where he had a broader audience was in movie houses, because Stanley Kubrick picked up some of his music for use in several of his films, most notably 2001: A Space Odyssey.Nervous types could relax; Romanian Concerto is from Ligeti’s early years, when he was working behind the Iron Curtain and constrained by the commissars’ detestation of music that trod forbidden paths.The only place that might have raised a few red eyebrows was the final movement (of four), in which the strings go Ligeti-split while conjuring up mysterious and somewhat abrasive sounds. The rest is really quite lovely, with some exceptionally appealing sounds in the strings and woodwinds. It was like something that Aaron Copland might have written if he had grown up in Romania and Hungary.The conductor of the evening was a guest, Joshua Weilerstein, assistant conductor of the New York Philharmonic. His appearance would have been worthwhile if he had done nothing else but introduce the Ligeti concerto to the audience. But he was an impressive maestro throughout the evening.For the Brahms concerto, he teamed with pianist Adam Golka, a young man very well known in the city’s musical circles because of his years at Texas Christian University studying with José Feghali.Golka and the orchestra gave a majestic performance of the Brahms. I particularly liked the second movement, in which Brahms alternates between passion and sweet lyricism — a contrast which was beautifully worked out —and the lovely andante, a movement that was so appealing to Leonard Bernstein that he took a theme from it for use in one of his musicals.Weilerstein and the orchestra achieved real grandeur in the opening movement of Sibelius’ Fifth Symphony (thanks for programming this one and not the overdone First or Second symphonies). Great swelling waves of sound filled Bass Hall.The woodwinds, including Kevin Hall’s eloquent bassoon, Ana Victoria Luperi’s clarinet and Jennifer Corning Lucio’s oboe, had a grand night, as did cellist Leda Dawn Larson in the Brahms.