Entrainment of walking with rhythmic auditory cues (e.g., metronome or music) induces gait improvements in people with Parkinson's disease (PD). However, evidence regarding acute impacts of music cues on parkinsonian gait is lacking. Findings in healthy adults imply that familiarity with music cues modulates stride amplitude and stride-to-stride variability; yet the role of familiarity with music on parkinsonian gait remains unknown. To investigate 1) whether familiar and unfamiliar music cueing differentially influences stride and arm swing amplitude and stride-to-stride variability, 2) how stride and arm swing amplitude and stride-to-stride variability are altered by enhanced familiarity with music by repeated listening and walking during rhythmically-cued walking in persons with PD. Twenty individuals with idiopathic PD (mean age = 68.9 years, 7 females, H&Y stage 1-3) walked in time with familiar and unfamiliar music cues (Session 1). Participants then repeatedly listened and walked to the same familiar and unfamiliar music cues (Session 2). Spatiotemporal gait parameters in each 2-min trial were recorded with motion capture wearable sensors. In Session 1, gait velocity, stride length, arm swing peak velocity and range of motion, and stride-to-stride variability increased with both music cues compared with baseline; stride length, enjoyment and beat salience were greater in familiar than unfamiliar music cues. In Session 2, repeatedly listening and walking to unfamiliar music, but not familiar music, increased gait velocity, stride length, familiarity, enjoyment, and beat salience, and reduced stride-to-stride time variability. Music cues in general induced acute improvements of stride and arm swing amplitude but not stride-to-stride variability, and enhanced familiarity with music improved stride amplitude and variability along with increased enjoyment and reduced cognitive demand in people with PD. Our findings aid in understanding the role of familiarity with music in alleviating gait disturbance and optimizing music-based interventions for PD.