> You just need to be aware that lisp is almost completely irrelevant in the real world.
Couldn't be further from the truth. For the last twenty years, most `new' languages have been basically reimplementing old Lisp (and sometimes Smalltalk) ideas. If you know Lisp, you can learn any of them quickly.
Anyway, your language oriented way of thinking is harmful. Beginners should learn abstract concepts of programming, not the idiosyncracies of some language. SICP uses Scheme for its simplicity; when you can learn the syntax in the first two chapters, you can focus on actual programming.