The researchers investigated music teachers' perceptions of the sources and difficulty of competency acquisition for music teaching. Participants (N = 338) were music teachers in Arizona, Texas, and Washington. Using categorized competencies for music teaching (music, teaching, or personal skills/knowledge), the researchers divided participants into three experience levels: novice, experienced, and veteran music educators. Participants viewed teaching competencies as the most difficult to acquire and personal competencies as the least difficult to acquire. Novice music educators perceived both teaching and music competencies as more difficult to acquire than veteran music educators, while veteran educators perceived personal competencies to be less difficult to acquire than both novice and experienced music educators. The majority of participants (77.5%) attributed teaching competency acquisition to job experience. The researchers found no significant differences regarding music teachers' perceptions of competency category acquisition difficulty related to teaching specialization, although item-level differences emerged.