When did Mozart write symphony no 25?
No. 1 in E flat major, at the age of 8! Magg811- Mozart started getting interested in piano at age 3, and became a master at the violin and piano at age 4 and created his first symphony at age 5. Not age 8. ...this is the first i have heard of him creating Symphony No. 1 at age 5. I believe that it was around the age of 8 or 9.