If there’s anything Ryan Gosling looks for in an acting assignment, it’s the ability to take a genre role, twist it off the standard interpretation and blindside the viewer.His romantic leads in Lars and the Real Girl and Blue Valentine were tender, vulnerable lost souls, while in Crazy, Stupid, Love he turned a handsome, misogynistic player into someone smart, sophisticated and semi-hilarious. He gave the adrenalized thriller Drive an action anti-hero who was hyperviolent and a bit arty, then zigged into film noir sado-masochism in Only God Forgives and zagged toward slapstick private eye satire in The Nice Guys.Occasionally he goes too far, packing on so much weight to play a grieving father in The Lovely Bones that Peter Jackson fired him and cast Mark Wahlberg in the part.In the stylish musical La La Land, he turns a struggling 30-something jazz pianist into a singing, dancing romantic lead with an almost angelic smile and a dark, melancholy soul. Through a series of chance meetings in overpopulated but lonely Los Angeles, he encounters the love of his life, an aspiring actress played by Emma Stone. In writer/director Damien Chazelle’s tuneful love letter to alluring Hollywood love stories, Gosling steps simultaneously into the tradition of giddy choreographed serenades and an elusive ambiguity about commitment that is utterly contemporary.Article Continued Below“There was a lot of preparation for this,” he said in a recent phone interview. He studied keyboard, song and dance, “thanks to my very patient and talented coaches. They were very, very, very good.“Did you ever see the film Cutting Edge? It’s about a hockey player trying to learn how to figure skate. I felt at times like that. I had had experience of dancing as a kid, but ’90s hip hop is a little different from tapping and waltzing.”Mandy Moore, choreographer for TV’s Dancing With the Stars and David O. Russell’s Oscar-nominated Silver Linings Playbook, supervised Gosling’s soft-shoe courtship.