Street performance or busking is common in public spaces. The literature highlights two psychological issues: the effect of street performance on public space perception and the complexity of the appreciation of street performance, regarded as street audience experience (SAE). The present study aims at verifying the effect of street performance on public space perception, while examining SAE as a mediator of this effect. We conducted a between-subjects field experiment (a quasi-experiment; N = 292) in Hong Kong. Participants assessed a public space without (control) or with (experimental) musical busking on essentialism, anti-essentialism, sonic restorativeness, and overall liking. In the experimental condition, unengaged passersby and engaged audience further evaluated SAE factors of emotion, intellect, novelty, place, interaction, and technique, and outcomes of overall satisfaction and donation worth. The public space with busking was perceived as significantly more sonically restorative. Engaged audience perceived the space as significantly more essentialist, anti-essentialist, sonically restorative, and likeable. Engaged audience also experienced more positive SAE and outcome variables. SAE fully mediated the effects of street performance on public space perception and outcome variables, respectively. These findings support the positive impact of street performance, which may enhance city inhabitants’ well-being.