While inattentional blindness is a modern classic in attention and perception research, analogous phenomena of inattentional deafness have been widely neglected. We here present the first investigation of inattentional deafness in and with music under controlled experimental conditions. Inattentional deafness in music is defined as the inability to consciously perceive an unexpected musical stimulus when attention is focused on a certain facet of the piece. Participants listened to a modification of the first 1'50″ of Richard Strauss' Thus Spake Zarathustra; while the control group just listened, the experimental group had to count the number of timpani beats. An e-guitar solo served as the unexpected event. In Study 1, experimental data from n = 115 participants were analyzed. Non-musicians were compared with musicians to investigate the impact of expertise. In Study 2 (n = 47), the scope of the inattentional deafness effect was investigated with a more salient unexpected stimulus. Results demonstrate an inattentional deafness effect under dynamic musical conditions. Quite unexpectedly, the effect was structurally equivalent even for musicians. Our findings clearly show that sustained inattentional deafness exists in the musical realm, in close correspondence to inattentional blindness with dynamic visual stimuli.