From the May 2011 edition of Third Way magazine:
"...I went on going to church and I think I had the same values, only no longer quite with belief behind them. I went on with church music, which I liked a lot. Religious music still moves me, in a way that I suppose it shouldn't, if you like. It's not something that a Christian would think of as religion, but it's a substitute." (Professor John Carey)
I think Professor Carey articulates something very important to understand: that it is possible to appreciate religious music (or art or whatever) in such a way as to gain some benefit from it, even spiritual benefit - but this is not the same as worship. I think I would want to describe the difference as being between a consumer of religiously flavoured produce and being engaged in a conversation with something other than our own desires and perspectives. It is the latter that counts as worship, not the former.