Felix Mendelssohn’s colleagues and contemporaries regarded the grand sonatas as the most important cycle of organ compositions since the time of Johann Sebastian Bach. They interpreted the expressive and dramatic movements of the Sonatas with poetic meaning, based on what a contemporary critic called their spiritual dimensions. This viewpoint challenges the common contemporary understanding and interpretation of these works. Widely considered one of the greatest organ virtuosi of his time, Mendelssohn played the cycle as a whole at an informal premier in Frankfurt in 1845. Conceived and perceived as a single large-scale work, the Sonatas seem to have a symphonic scope. Yet, eighteenth-century central German organs were Mendelssohn’s preferred style. The descriptions of Mendelssohn’s sensitive touch, differentiated articulation, brilliant technique, and expressive playing, as well as his original metronome indications, inspire us to take a fresh approach to the Sonatas. In recent years, Hans Davidsson’s studies of the Sonatas and early nineteenth-century performance have brought new perspectives to our understanding of these works. Traditionally the individual Sonatas might be “authentically” played as single, separate pieces on a German Romantic organ, contemporaneous with Mendelssohn’s lifetime. Instead, Davidsson has chosen to play the complete eighteen-movement cycle on an early nineteenth-century organ, an instrument with unique character, sensitivity, transparency, and rich color. For the performer, this instrument brings new interpretive possibilities to the Sonata cycle, based on what is known about Mendelssohn’s own performances. For the listener, these new interpretations are given voice on one of the best preserved historical organs in northern Europe- the instrument built for the church in Gammalkil, Sweden, by Pehr Schiorlin in 1806.