A Novel by Mary Roach
Many of these songs are from different genres because, while the theme of the book is death, death can be seen from many different perspectives, and not all of them are dark.
Song #1: Safety Dance - Men Without Hats
The beginning of the book goes over the general ideas of the afterlife, with Mary in India during this time. In my opinion, this song fits the theme of this part of the book because of the subject of reincarnation, as well as a portion of the section of the book where they were stuck in traffic. The traffic portion seemed somewhat comical and bright, which reminded me of this song.
Song #2: Carry On My Wayward Son - Kansas
While this song has a strong connection with Supernatural, that's only part of the reason I picked this song. Following the theme of death and the afterlife, I feel that this song perfectly captures what the afterlife means.
Song #3: Down Under - Men At Work
This song reminds me of Hades and the Underworld in that its lyrics could be seen to describe a hellish world with mentions of greed, temptation, and confusion. All of those things are associated with death and the afterlife, and so I thought that it fit well.
Song #4: Don't Fear The Reaper - Blue Oyster Cult
Finally, this song encompasses the general idea that the book tries to capture. That is, death is not something to fear, but rather embrace. In the end, no matter what you do, you really can't know what death is like until it happens.