Q: A song is missing from my iTunes library

I have an iPhone 6, I was listening to my music and noticed that a particular song was missing. I bought it from iTunes and everything but I can't find it anywhere. When I searched for it on the iTunes store on my phone it said it was purchased but there was no option I could find to try to redownload it. It used to be in my library but for some reason isn't anymore. When I went to the iTunes library on my computer and searched for it, there was only an option to buy it but I already bought the song. The song is We Don't Have To Dance by Andy Black. Any recommendations on