"I have to sing goofy... in order to sing. Like I have to sing stupid. " This the unnecessary disclaimer from Dean (Ryan Gosling), as he's about to serenade Cindy (Michelle Williams) in front of a Brooklyn dry cleaners one evening, early in their swoony courtship. If you've seen the trailer for Blue Valentine , or the film itself, you've heard Mr. Gosling's "stupid" singing, a kind of throwback yodel of "You Only Hurt the One you Love," that occurs while he strums a ukulele. Cindy provides a shuffling, ragged tap dance. The singing and dancing are both so beautifully goofy that it's hard to imagine not falling in love with either Dean or Cindy in that moment. Unfortunately, the couple and the film have to leave the cozy entryway of the Brooklyn dry cleaners with the heart-shaped wreath on the front door. You know, the inexorable march of time and all that. Blue Valentine , for its part, goes back a...