Background: Playing-related musculoskeletal disorders are the most frequent complaints among instrumental musicians. The aims of this study were: to assess the prevalence of musculoskeletal pain; to evaluate neck, shoulder, and lower back disability; and to determine the associated factors with the presence of musculoskeletal pain among musicians. Methods: A population-based, cross-sectional descriptive study was conducted. We selected Spaniard musicians over 16 years old who played a musical instrument for at least five hours per week. They answered the Spanish versions of the Standardised Nordic Questionnaire, the Oswestry Disability Index, Neck Disability Index and Shoulder Pain and Disability Index. Results: We found 94.8% of musicians presented at least one symptomatic region in the last 12 months, and 72.3% in the last seven days. Female musicians (OR 4.38, CI 2.11−9.12), musicians with overweight or obesity (OR 5.32, CI 2.18−12.97), and musicians who play more than 14 h per week (OR 3.86, CI 1.80−8.29)were shown to be a higher risk of suffering musculoskeletal pain. Conclusions: Musculoskeletal disorders symptoms are highly prevalent in musicians. The main risk factors related to musculoskeletal disorders symptoms were gender (being female), overweight, obesity, and spending playing more than 14 h a week practicing. This study highlights the need to provide strategies to prevent occupational disabilities among musicians. Further studies are needed to analyse the prevalence of pain in the musician using other sampling methods.