On Borrowing Tunes

At shul this morning, they used a few tunes borrowed from the Christian world for a couple of the hakafot.  The first one came as a touch of a shock, as I know it only from singing it with the hospital choir this summer (3-7 people, depending on the week.  We sang at bedsides once a week, for about an hour)- I'll Fly Away.  After the first time we did it, it was stuck in my head for about 2 weeks (and will probably be back there for a while).  (Note the lyrics to the chorus: "I'll fly away, O Lordy, I'll fly away/When I die halleluyah by abd by I'll fly away"- an odd thought to combine, but I figured ok, it sort of works.)  Then a bit later we got Amazing Grace, which oddly enough fit the topic better.  Never thought that I'd say that.