There have been many string orchestras over the past 200 years. Some are famous. I based my string orchestra piece on S. Barber’s Adagio - based on feeling and expression.
The musical theme is barely tangible and blurred in the harmonic progression. The atmosphere is much more important.
This piece is in 4/4 time with a bpm 110 and it is an ABA form. Actually pretty simple and straightforward. The ending chord keeps it all open because it’s not the tonic, but I think it’s an ending.
Have a listen and feel the pain.