Two new movies pay tribute to musical instruments and/or traditions that haven't always gotten their due in mainstream USA. In part one, Tad Nakamura, director of "Jake Shimabukuro: Life on Four Strings." It's a moving portrait of the musician who's taken the yukulele—-sometimes wrongly dissed as a novelty instrument—-to virtuosic heights. In part two, Tom Gunderson director of "Mariachi Gringo," the tale of a young man from the midwest who falls in love with Mexico and devotes himself to mariachi music. Lead actor Shawn Ashmore devoted himself to the music too, going to school on vihuela. The film also includes Mexican diva Lila Downs.