Ludwig van Beethoven was a German composer and pianist. A crucial figure in the transition between the Classical and Romantic eras in Western art music, he remains one of the most famous and influential of all composers. His best-known compositions include nine symphonies, five piano concertos, one violin concerto, 32 piano sonatas, 16 string quartets, his great Mass the Missa solemnis, and one opera, Fidelio. Together with Mozart and Haydn, he was part of the First Viennese School. Born in Bonn, then the capital of the Electorate of Cologne and part of the Holy Roman Empire, Beethoven displayed his musical talents at an early age and was taught by his father Johann van Beethoven and by composer and conductor Christian Gottlob Neefe. At the age of 21 he moved to Vienna, where he began studying composition with Joseph Haydn, and gained a reputation as a virtuoso pianist. He lived in Vienna until his death. By his late 20s his hearing began to deteriorate, and by the last decade of his life he was almost totally deaf. In 1811 he gave up conducting and performing in public but continued to compose; many of his most admired works come from these last 15 years of his life.

Johannes Brahms was a German composer and pianist. Born in Hamburg into a Lutheran family, Brahms spent much of his professional life in Vienna, Austria. His reputation and status as a composer is such that he is sometimes grouped with Johann Sebastian Bach and Ludwig van Beethoven as one of the "Three Bs" of music, a comment originally made by the nineteenth-century conductor Hans von Bülow.
Brahms composed for symphony orchestra, chamber ensembles, piano, organ, and voice and chorus. A virtuoso pianist, he premiered many of his own works. He worked with some of the leading performers of his time, including the pianist Clara Schumann and the violinist Joseph Joachim (the three were close friends). Many of his works have become staples of the modern concert repertoire. Brahms, an uncompromising perfectionist, destroyed some of his works and left others unpublished.
Brahms has been considered, by his contemporaries and by later writers, as both a traditionalist and an innovator. His music is firmly rooted in the structures and compositional techniques of the Classical masters. While many contemporaries found his music too academic, his contribution and craftsmanship have been admired by subsequent figures as diverse as Arnold Schoenberg and Edward Elgar. The diligent, highly constructed nature of Brahms's works was a starting point and an inspiration for a generation of composers. Within his meticulous structures is embedded, however, a highly romantic nature.

Modest Petrovich Mussorgsky was a Russian composer, one of the group known as "The Five". He was an innovator of Russian music in the romantic period. He strove to achieve a uniquely Russian musical identity, often in deliberate defiance of the established conventions of Western music.
Many of his works were inspired by Russian history, Russian folklore, and other nationalist themes. Such works include the opera Boris Godunov, the orchestral tone poem Night on Bald Mountain and the piano suite Pictures at an Exhibition.
For many years Mussorgsky's works were mainly known in versions revised or completed by other composers. Many of his most important compositions have posthumously come into their own in their original forms, and some of the original scores are now also available.