I am a huge fan of The Good Wife. The strengths of this show are its acting, style, character development, and ability to juggle many plot lines at once. Through the years, I have never grown tired of the show, and haven't missed an episode.
That said, I think this episode lacked imagination. Rowby Canton depicted as a ditzy musician was probably intended as comic relief, but it was a rather hackneyed and tiresome characterization. Musicians the world over were probably cringing through this episode, since professional musicians are well acquainted with the ins and outs of copyright infringement.
I agree with another reviewer's comments about the unbelievability of Marilyn's naïveté as well, as well as Kalinda's tryst with someone so obviously deceptive. It is undoubtedly difficult to come up with ways to make use of an intriguing character like Kalinda, who was, for many viewers, a huge reason to continue watching. But it's necessary to maintain her credibility, something that got damaged during the ongoing saga of her ex-husband. It would make sense, for instance, to call into question what she ever did to be rid of him forever.
Please stay strong and smart in your character development, Good Wife show runners. You've done better.