At first, there are four tracks of all smokey Clavier. It sounds narrow without any sense of space. I changed the instrumentation with the following list: Classical Acoustic Guitar, Smokey Clavier (High voice), Smokey Clavier (Low voice), and Tight Synth Bass. I adjusted individual pan position, master dynamic, master EQ setting to Hi-Fi, and master Compression to Classical Warm.
The result is 95% satisfactory to me. There is one problem with the Classical Acoustic Guitar. When it plays fast trills, it is accompanied with some high-pitched rubbing sound. I don't know how to eliminate that sound. So I left it there. If I have more time, I may add some background sound, like wind or bird chirping sound, to cover that high-pitched rubbing noise.
Please click this link to get its sound track.