Musical training is popularly believed to improve children’s cognitive ability. Early research evidence, mostly correlational, suggested that musicians outperform nonmusicians on many cognitive abilities. However, recent experimental evidence has failed to replicate most benefits, leaving it unclear whether previously demonstrated effects were a direct result of learning music. Although a few studies have shown some change with as little as a few weeks of training, the larger training literature shows that transfer of skills between unrelated areas is extremely rare, especially in properly controlled studies. The current study used an experimental design to assess the cause (whether music uniquely produces change) and the effect (which cognitive abilities are impacted) of the link between music and cognition. Six- to 9-year-old children (n = 75) with no prior training were randomly allocated to 3 weeks of music or dance training. Cognitive performance before and after training was compared between trained groups, because both training forms share features of training plus a nontrained control group to isolate training-induced change from normal maturation. No changes were found on any measured ability (inhibitory control, working memory, task switching, processing speed, receptive vocabulary, and nonverbal intelligence). Findings confirm evidence from the general training literature that training-induced improvements on cognitive performance are unlikely. Short-term training effects have a much narrower scope than previous evidence suggests. (PsycINFO Database Record (c) 2018 APA, all rights reserved)