I was gonna mention the Tolliver disc too, but Sangry beat me to it.
This probably isn't what you're looking for, but for what it's worth - there was a one-off concert that Sun Ra did with strings, probably in the mid 80's or so. About a dozen string players, if I remember right. I'm pretty sure it's on Leo, and the AMG review of another (different) Sun Ra disc mentions that the Leo release "Pleiades" has about a dozen French symphony musicians on it, so I'm guessing that's the one. (No AMG review for "Pleiades" - however.)
No time to check up on it now, I'll look again later tonight.