There are lots of classical interpretations of the Beatles repertoire.
The album you've been told of is actually two volumes issued in 1978 and 1979 called "Francois Glorieux Plays The Beatles". They have been reissued as "The Beatles from Bach to Bartok" in Belgium I think.
There are other interpretations of course. One of the most famous is "The Beatles Baroque Book" by Joshua Rifkin issued in 1965. Sadly this hasn't been reissued in cd. You can search also for Peter Breiner's "Let it be...J.S. Bach" (reissued as The Beatles Go Baroque, on Naxos)