Well, I consider that music is made in Heaven, right? Angels are singing songs, melodies are being made, and people are worshiping the Lord. So, in this respect, imagination is in full swing and creativity is alive and well. As far as fantasy is concerned, well an apostle couldn't even repeat the things he saw (in Heaven) otherwise people would think he was crazy; so as the saying goes, "truth is stranger than fiction." We might just be amazed at how fantastical reality is.