Romantic era pop star

When people talk about "Classical" music, they usually mean Western art music of any time period. But the Classical period was actually a very short era, basically the second half of the eighteenth century. Only two Classical-period composers are widely known: Mozart and Haydn.

The Romantic era produced many more composers whose names and music are still familiar and popular today: Brahms, Tchaikovsky, Schumann, Schubert, Chopin, and Wagner are perhaps the most well-known, but there are plenty of others who may also be familiar, including Strauss, Verdi, Liszt, Mendelssohn, Puccini, and Mahler. Ludwig van Beethoven, possibly the most famous composer of all, is harder to place. His early works are from the Classical period and are clearly Classical in style. But his later music, including the majority of his most famous music, is just as clearly Romantic.

The term Romantic covers most of the music (and art and literature) of Western civilization from the nineteenth century (the 1800's). But there has been plenty of music written in the Romantic style in the twentieth century (including many popular movie scores), and music isn't considered Romantic just because it was written in the nineteenth century. The beginning of that century found plenty of composers (Rossini, for example) who were still writing Classical-sounding music. And by the end of the century, composers were turning away from Romanticism and searching for new idioms, including post-Romanticism, Impressionism, and early experiments in Modern music.