Music performance anxiety (MPA) is a phenomenon often encountered among professionals and students who make public appearances. This article presents the results of a study carried out on a sample of music students in superior music conservatories in Spain (N = 434). Our goal was to analyze MPA on the basis of Barlow’s (2000) anxiety theory, supplementing it with further personality constructs such as dispositional optimism, general auto-efficacy, and sensitivity to reward and punishment. Our structural equation modeling (SEM) results reveal that several of those constructs exert their effect via the helplessness factor – the central construct in Barlow’s theory – and that they likewise exert a further series of direct effects on MPA. All in all, the variables taken into consideration account for 45.6% of variance in MPA in males and of 52.1% thereof in females. This study thus upholds Barlow’s theory of anxiety, while broadening it with further explanatory mechanisms.