EinsamKeit, is a custom made, portable musical instrument which allows the audience to perform famous classical compositions. As a musical instrument, the object suggests a need for practice and skill which are typically recognized as foundations of mastery. However, EinsamKeit is a keyboard equipped with only one key. This unique design proposes a paradoxical situation in which the user navigates the vast territory of musical history, theory and practice, while engaging in a mindless act of repeatedly pressing a single key. Each keystroke advances the playback of a pre-recorded concert, confronting the relationship between the nature of live vs. recorded musical performance. EinsamKeit manages to seamlessly connect two events marking the end-points of the musical spectrum: the basic event of pressing a singular key on a keyboard, and the professional audio recording of a masterful musical performance. EinsamKeit compresses the beginning and the end of this musical process into a playful user interaction.