Glee is nearing the end of season 4, and they couldn't let the season go without doing another tribute episode. This time, instead of another pointless homage to Britney Spears, they're paying tribute to the legendary Stevie Wonder. Along the way, Artie is faced with news that'll affect his future, and we're introduced to his mother, played by Katey Sagal. Rachel prepares for her callback audition for Funny Girl. And Mercedes, Mike and Cassandra July (Kate Hudson) make return appearances.