The research objective of the study was the investigation of the immediate effects of an individualized music intervention in a nursing home using a newly developed systematic behavioral observation rating scale. In 153 behavioral observations of 20 PwD, 32 different experiences and behaviors pertaining to 11 categories such as emotional and motor changes which indicate immediate reactions to listening to music were rated. Participants showed significantly more positive reactions (e. g. joy or relaxation) and less negative reactions immediately after listening to the music compared to before. Moreover, in the course of listening to music, participants showed significantly more positive reactions, most often smiles, movements to music, attentive listening, relaxation and general vigilance / interest / social contact. The systematic behavioral observation rating scale proved to be a suitable method for rating the experiences and behaviors of people with dementia. Listening to individualized music seems to be a helpful intervention for PwD in institutional care settings.