Kevin Santiago, from left, Liam Larsen, Esmeralda Martinez blow on their trombone mouthpieces during their trombone lesson offered by Harmony Project, a Los Angeles-based nonprofit that provides free music lessons to low-income students, Thursday, Aug. 28, 2014, in Los Angeles. A two-year study of dozens of schoolchildren from disadvantaged Los Angeles neighborhoods shows that music training changes the brain in ways that make it easier for youngsters to process sounds, according to results reported in Tuesday's edition of the journal Neuroscience.