You can describe a person unable to read or write as illiterate. Karaoke, which involves singing out the words to songs as they scroll across a big screen, requires the ability to read. If you’re illiterate, you won’t be able to participate.
Illiterate, from the Latin illiteratus “unlearned, ignorant,” can describe someone unable to read or write, but it can also imply that a person lacks cultural awareness. However, Walt Whitman saw a unique beauty to illiteracy: “There is that indescribable freshness and unconsciousness about an illiterate person that humbles and mocks the power of the noblest expressive genius.”