Short answers, pulled from the story.
Wolfgang Amadeus Mozart completed his Piano Concerto No. 9 in E major, K. 271 during the winter of 1777. He finished the work specifically in January of that year while he was twenty-one years old.
Michael Lorenz proved in 2006 that the dedicatee of Wolfgang Amadeus Mozart's Piano Concerto No. 9 was Victoire Jenamy. She lived from 1749 until 1812 and was a French virtuoso pianist who performed in Salzburg during December 1776.
The score for Wolfgang Amadeus Mozart's Piano Concerto No. 9 calls for solo piano accompanied by two oboes and two French horns in E. Strings complete the orchestral forces required for the piece along with these wind instruments.
Théodore de Wyzéwa and Georges de Saint-Foix claimed Mozart wrote the piece for an unnamed French pianist named Jeunehomme which means young man in French. Michael Lorenz later demonstrated this name was a misinterpretation because the dedication actually belonged to Victoire Jenamy all along.
Three movements structure the entire work of Wolfgang Amadeus Mozart's Piano Concerto No. 9 from beginning to end. The second movement shifts into the relative minor key while the third movement returns to rondo form on a large scale.