The sixth and last Mendelssohn's quartet is a masterpiece

[Spotted Horses]

I enjoy the Emersons in so much else, I was thinking of their Mendelssohn, but I am glad the Fickle Finger of Fate pointed me instead to the Pacifica set.

...based on 10 seconds, mind you. But I am not generally a fan of the Emersons, despite the obvious technical perfection.

[W.A. Mozart]

Oh, how true!! I adore this quartet so much that I even orchestrated it - what a power and desperation!! https://youtu.be/1mAUlPdXpms?si=vdfkISuUx-qgu_Sq

Nice, although it's clearily played by a software and not by a real orchestra. However the time seems quite wrong.

In the recording I have the first movement is considerably shorter.

[W.A. Mozart]

Why?

Why not? It's not uncommon to create orchestral arrangements of chamber works. Copland and Elgar for example orchestrated some of their chamber works.