Prior studies have identified the impact beliefs have on mathematics instructors' instructional practice, such as their choice to (or not to) lecture. However, the role of instructional context role in influencing beliefs and instruction has not been thoroughly researched. This paper explores how course context and beliefs could impact mathematics instructors' propensity to lecture by investigating two very different instructional contexts in undergraduate mathematics in the United States: Calculus and Abstract Algebra. The results of our regression analyses were significant in both data sets and, we did find beliefs in each context that predicted the amount of time spent lecturing. For instance, the more calculus instructors believed in the effectiveness of teacher-centered instructional practices, the more likely they were to lecture. Whereas the more abstract algebra instructors believed in their student's capacity to learn the less likely they were to lecture. However, while the regression model for the abstract algebra instructors accounted for 37.8% of the variability in the reported amount of time spent lecturing, the model for Calculus instructors only accounted for 2.7% of the variability. Thus our analyses indicate that there are contextual differences, such as course coordination, student demographics, and the job security of the instructors, that may be mitigating the extent to which beliefs impact instructional practice.