Common Lisp for Schemers

What's the best way for a Schemer to learn Common Lisp? It seems like Scheme itself is a more beautiful language, but the efforts made by many implementations to make Scheme useful "in the real world" lead to a big ball of mud™. Does Common Lisp avoid this problem? Should I keep trying to learn different Scheme implementations instead until I find something I like?

>>1
No, Common Lisp does not evade this problem. It is much more beautiful than Scheme (particularly its macros, its condition-return system, and its CLOS and MOP), but still a huge ball of mud and crutches. Common Lisp hasn't changed since the nineties and is a very old and antiquated language.
Quit Lisp and learn a real world language instead.