Symphony, K. 45a (Mozart) implies that K. 45a was composed by Wolfgang during their stay in The Hague, possibly for the inauguration of William V, Prince of Orange on 11 March 1766. The Mozarts then took the symphony along with them on their journeys; Wolfgang revised the symphony along the way by making a few changes, especially in the inner voices. Symphony, K. 45a (Mozart) The Symphony in G major "Old Lambach", K. Anh. 221/45a, was probably written by Wolfgang Amadeus Mozart during 1766 in The Hague and revised in 1767. Both versions – the original and the revision – have survived. The symphony
Wolfgang Amadeus Mozart person and repute, he has taste and what is more the greatest skill in composition." From 1782 to 1785 Mozart mounted concerts with himself as soloist, presenting three or four new piano concertos in each season. Since space in the theaters was scarce, he booked unconventional venues: a large room in the Trattnerhof (an apartment building), and the ballroom of the Mehlgrube (a restaurant). The concerts were very popular, and the concertos he premiered at them are still firm fixtures in the repertoire. Solomon writes that during this period Mozart created "a harmonious connection between an eager composer-performer and a