Many scholars have advocated the addition of more intellectual activities in music classrooms, the most prominent being critical thinking through inquiry. Inquiry-based learning (IBL) has been recognized as necessary for teaching and learning that increases critical thinking skills and dispositions. This study describes an extensive list of indicators that could ascertain the pedagogical practices and intellectual quality of knowledge work indicating the strength of inquiry in music classrooms. It shows the relationships between these indicators that help us understand the enablers and hindrances to critical thinking as an aspect of IBL in music. The article focuses on the Descriptive Statistics results of 114 classroom observations for music at the Primary and Secondary levels, using coding schemes developed in the Singapore Core3-PP project from 2018 to 2020. The results confirm the gap identified in the literature that music classes lack significant inquiry work that would nurture critical thinking skills and dispositions. The findings provide pedagogical insights that can (a) inform educators on how to examine and grow their IBL practice in music lessons; (b) move music education's objective toward a balanced development of music skills and knowledge construction; (c) develop critical musicality and independent musicianship among students; and (d) provide concrete measures for researchers to design interventions in the areas of teacher learning in IBL.