Now that our nation’s dueling, mediocre, pop-detecting machines, American Idol and The Voice, have come to positively underwhelming conclusions, ABC is filling the summer gap with Duets. Featuring four superstar performers — the word “superstar” is used loosely and often on this show — Duets hopes to discover the world’s best duet partner (we think?) by having Kelly Clarkson, John Legend, Sugarland’s Jennifer Nettles, and Robin Thicke perform their biggest hits (and “biggest” “hits”) alongside relative unknowns. Other pertinent facts: This show is hosted by former MTV VJ and ghost of your youth Quddus; the tagline is “Will you duet with me?”; it is nearly impossible to understand how one is meant to win the show at the conclusion of its nine episodes. In other words, your Thursdays nights are all set for the rest of the summer. Sad singing-show addicts Juliet Litman and Sean Fennessey watched last night’s inaugural episode in search of rhyme, reason, an easily understood voting system, and some answers about Jennifer Nettles’s face.