As museums have started focusing on interactive and experience-centered exhibits, the need for installations designed specifically for this setting is increasing. This paper investigates how an exhibit, with the aim of communicating complex synthesis, can be developed in order to facilitate an exploratory and playful sonic experience. In collaboration with The Danish Music Museum, a granular synthesizer, allowing real-time audio recording and manipulation, is combined with LED visuals, to create an immediately playable instrument. The sonic aspects of granular synthesis are communicated through the analogy of rain, and the instrument is designed to specifically target children and novice users. Through walkthrough demonstrations and task-based usability evaluation, the instrument was evaluated. Whereas no conclusion can be made about the instrument’s communicative features or artistic message, results indicate a low entry-fee and a user-friendly product.