9 seconds time code
or bar 4-5
After a soft graceful theme 1 of exposition in E flat major. Sudden loud Eb major scale leading to an Eb diminished 7 chord.
WOW that moment is awesome. I've been replaying that moment numerous times recently.
I may have to upgrade the concerto from a 2 star (from my previous rating) to a 3 star just for that really unexpected Eb diminished 7th chord