A Christian's funeral should be simple, honorable, and hopeful in tone. Accordingly, our tone at the funeral should be biblical. I think, as a rule, only Christian music should be used. At my funeral, I'd rather we'd sing All Hail the Power of Jesus Name than Achy, Breaky Heart. I also suggest that anyone who ministers in song stand before the congregation, where they can comfort the family with their countenance.
Most funeral homes have a little backroom containing an organ, a microphone, and a tape player.
That's where they often put anyone who is going to minister in music. If it's true for the sermon, it's true for the song. The only time some people ever hear the Bible is when they come to a funeral, and it may be their one and only time to hear the Gospel. I also recommend that the family's time of receiving friends be limited. The next morning, a private graveside service is planned for the family.