Treatment of chronic pain in patients with dementia is challenging because they have reduced ability to report pain and are particularly vulnerable to side effects of analgesics. Different types of music-based therapy have been recommended and are used as an alternative to analgesics, but the evidence is lacking. Therefore, we performed a cluster-randomized controlled study (RCT) to reduce pain intensity using music-based caregiving (MBC) over 8 weeks in nursing home patients with dementia and chronic pain. We also investigated if the amount of MBC and different chronic pain syndromes would impact on the effect. Of the 645 patients, 498 patients from 36 wards in 12 nursing homes were screened for dementia and pain. Using the Clinical Dementia Rating Scale and the Mobilization-Observation-Behavior-Intensity-Dementia Pain Scale (range 0-10), 279 (71% females, 42% severe dementia) nursing home patients were randomized to intervention group (n = 134, 18 wards) or control group (n = 145, 18 wards). The main outcome was change in pain intensity before and after the intervention. The study did not reveal any effect of MBC on pain intensity when compared with the control group (B = -0.15, 95% CI [-0.72 to 0.43]). No significant difference was found within the intervention group analyzing the impact of intervention time (B = 0.73, 95% CI [-0.55 to 2.02]) or chronic primary vs secondary pain syndromes (B = 0.45, 95% CI [-0.05 to 0.96]). Our data from this first RCT on music and pain intensity in patients with dementia and chronic pain did not find an effect of MBC on pain.