Rolling Stone - 3 stars out of 5 -- "'Invincible' is a triumphant power ballad co-written by go-to pop-diva tunesmith Sia."
The gleaming surfaces of Piece by Piece offers evidence that during the four-year hiatus between 2011's Stronger and this 2015 release, Kelly Clarkson and 19/BMG spent considerable time figuring out which direction she should pursue as she entered the second phase of her career. Instead of consolidating the assured mature pop of Stronger, Piece by Piece refurbishes Kelly, piling on EDM accouterments and finding her singing cuts co-written by such successful contemporary pop hitmakers as Sia ("Invincible"), Matthew Koma ("Someone"), and MoZella ("Take You High") on an album largely produced by Greg Kurstin, who has had hits with Sia, Tegan and Sara, Ellie Goulding, and Lily Allen. Previously, Kurstin proved to be a good fit for Kelly -- he produced three cuts on Stronger, including its title track -- and his decision on Piece by Piece is to emphasize sound, not song. Clarkson nevertheless performs as powerfully as ever, as illustrated by Sia's "Let Your Tears Fall" with its appealing nocturnal pulse, "Good Goes the Bye" floating upon its percolating beats, and "Nostalgic," a nifty piece of neo-new wave. These cuts, along with the title track, manage to strike the right balance of Kelly's indomitable character and fresh electronic beats. ~ Stephen Thomas Erlewine