Classical music venues in the Netherlands and throughout the world are struggling to attract new audiences. Especially younger visitors are underrepresented. Previous research emphasizes the importance of providing new, potentially interested audiences with more means to consume the music. This paper presents an exploratory case study with the persuasive game Listening Space which we developed to help attract new audiences and thus preserve Western classical music heritage. In particular, we studied to what extent this game could promote more varied ways of listening to classical music and thus enrich the experience of visiting a classical music concert. We designed and executed a controlled randomized trial with surveys before and after the experiment as well as a series of in-depth interviews with participants after the experiment. Our treatment group consisted of 139 participants (both new and existing visitors). They played our digital game at their own convenience, followed by a visit to a concert in a renowned classical music concert hall. A control group of 165 participants only visited the concerts. We measured the effects of the game - changes in the ways participants listen to classical music - through self-report in questionnaires before and after the experiment. Results show that Listening Space seems most effective for new audiences: the game promoted more varied ways of listening in the treatment group and thus enriched their experience of visiting a classical music concert. The control group of new visitors did not show an effect and also no differences were found between the treatment and control groups of regular visitors of classical music concerts We employed regression analysis to identify predictors of the game's effect on listening styles: participants' age and their level of appreciation of the classical music genre were negatively related to the effectiveness of the game. The way in which participants experienced the game also significantly influenced the effectiveness. This case study shows the potential of using games to promote classical music concerts: games seem to be valuable in attracting new, young audiences and, therefore, represent powerful instruments to help preserve Western classical music cultural heritage.