Wolfgang Amadeus Mozart wrote 27 concertos for piano and orchestra. These works, many of which Mozart composed for himself to play in the Vienna concert series  held a special place for him; indeed, Mozart's father apparently interrupted him composing a "harpsichord concerto" at age 4. Perhaps the most controversial aspect of the concertos is the extent to which Mozart (or other contemporary performers) would have embellished the piano part as written in the score. Mozart's own ability to improvise was famous, and he often played from very sketchy piano parts. 

The Piano Concerto No. 17 KV. 453 dating from the so called  “Major Vienna Works”. In these works of his mature series, Mozart created a unique conception of the piano concerto that attempted to solve the ongoing problem of how thematic material is dealt with by the orchestra and piano. The concerto was completed on April 12, 1784.

'duh-duh-duh-duuuh' -  Symphony No.5 of Ludwig van Beethoven is one of the best-known compositions in classical music, and one of the most frequently played symphonies. Beethoven was in his mid-thirties during this time; his personal life was troubled by increasing deafness. In the world at large, the period was marked by the Napoleonic Wars, political turmoil in Austria, and the occupation of Vienna by Napoleon's troops in 1805. The Fifth Symphony was premiered on 22 December 1808 in Vienna, and directed by Beethoven himself.