First of, Holst. Not Holzt's. Second, pick an instrument to learn, and play its part. French horn has most of the cool melodies if I recall.

But Mars isnt holst's best work. In fact, its not even his best suite from The Planets. You should check our Jupiter. Also, his second suite for military band is excellent
Also, if your really into those dark fanfares, you should check out shostakovich 5. Particularly the fanfare in the first movement