I really don't want to mix the two(mass/funeral) by my wife's grandmother pasted away a couple months back. We had a funeral with a mass. There was a woman there who sang ONE song. She was an amazing singer and it was a beautiful song. She brought EVERYONE to tears. The mass/funeral continued after she was done, and everyone commented on the amazing singing after all was said and done. We were there for a funeral and the ONE song really complimented the funeral. Had she then gotten up and sung 4 more songs mixed throughout the funeral, then that would detracted from the service.
I don't see that example and a mass any differently. All my regular masses now have like 4-5 songs and it takes away from why we are all there.