The purpose of this study was to examine the concerns of preservice music teachers using the Fuller and Bown teacher concerns model. Participants were 12 senior-level instrumental music education majors enrolled at a medium-size American public university. A video-assisted, stimulated recall method was used to interview participants after two peer-teaching and two field-teaching episodes. Data consisted of 1,019 coded statements drawn from more than 900 min of interviews. Task concerns were the most reported in all interviews, followed by self concerns and student impact concerns. Task concerns decreased across the four teaching episodes, while student impact concerns increased from the first field-teaching episode to the second. Rehearsal strategy use, evaluation of teaching, and individual student impact were the most frequently coded task, self, and student impact concerns, respectively. Overall, participants reported that peer teaching was more difficult and stressful than field teaching. Implications of the Fuller and Bown framework as well as additional future research directions are proposed.