Mozart's Symphonie Concertante - Allegro Maestoso Part 1 

Symphonie Concertante pour violon et alto. Performed by the Solistes de Versaille. Director - Bernard LeMonnier. Violin - Beatha Halka. Viola - Theodore Coman. Sorry, but due to the lengths of the first and second movement, I've had to chop them in half. Allegro Maestoso is the first movement. The second is Andante, and the third is Presto (one piece!)
I can't figure why RU-vid has a 10 minute limit. 20 would be better. Quite a few Symphonies have a first movement in particular which exceeds 10 minutes. I guess the folks who started YT had no idea that people would upload Great Music!