Common Lisp or Scheme?

I'm going to get some basics on functional programming. But there are too fucking many LISP dialects. I know all in all it's all the same shit, but between the two, which one should I use for these little studies?

(And yes, SICP is part of them)

>>14
It's only inefficient and ugly because you don't know how to write it better.
I need a pointer into the middle of array. There is no way to do it in CL, except passing array+index everywhere.