'Smile' review: Katy Perry is a sad clown in return to pure pop

'Smile' is a course-correction back to pure pop for Katy Perry, with no featured artistes and no political messages.

Katy Perry has two very personal projects being released this summer — the 12-track album Smile and a baby. Only one will really make people grin.

Smile comes three years after the dismal release of Witness, a criminally under-appreciated album that’s considered a commercial dud.