By the time students reach upper elementary school grades, they have had 4 or 5 years of school and are expected to have a modicum of knowledge. Music educators who include elements of history, culture, geography, or other social study in their music lessons presume students have some background knowledge to foster learning new information in music. When teachers must fill in knowledge gaps, it can be more difficult to teach music. Over the past years, curriculum narrowing has been felt by more than just classroom teachers; collateral damage exists for teachers of other subjects as well. This study was designed to evaluate if and to what degree music teachers in northwestern Illinois recognized any impact of curriculum narrowing, primarily in social studies. Through quantitative questionnaires, focus groups, and interviews, teachers' experiences and opinions of music teaching in upper elementary school was examined. Recent legislation such as No Child Left Behind with high-stakes testing in reading, language, and mathematics has affected classroom instruction in a great many schools in northwestern Illinois. This study probed how testing in schools influenced music class instruction as well as general aspects of teaching in schools, often schools that have not met state requirements for student learning. Music teachers responded that there were multiple and varied impacts of curriculum narrowing. High-stakes testing showed little impact of recent curriculum narrowing in social studies but much greater impact on all teachers in schools. Music teachers were being required or encouraged to augment classroom knowledge that would be tested. Often music teachers had to assist in the testing itself and were encouraged to supplement classroom knowledge in preparation for testing in language or math.