Band of an instrumental piece played in march 1971 on a FM station from Muncie, IN?


Starts with an orchestra playing a sort of Overture that as it fades away from the background a drum and a bass guitar comes forward before the lead guitar or electric violin starts playing a fantastic rock piece, kinda progressive kinda clean rock. Haven't stop searching since march 1971 with no luck.
cromagnon7
Could it be New York Rock & Roll Ensemble's track called Brandenburg?  I think the album Faithful Friends was released in 1967.
I think the electric violin has to be the clue here.  Please let us know if you ever find the answer.  I'm shooting for an early progressive bands called "If" or the Italian band PFM.  
Was it a long song? Was the radio station a free format station or top 40?

Atom Heart Mother by Pink Floyd released in 1970 kind of fits your description

https://www.youtube.com/watch?v=Fku7hi5kI-c