Louis Couperin's collection of fourteen Unmeasured Preludes for harpsichord presents a variety of interpretational challenges for the modern musician. There are no metrical markings or interpretational instructions, nor, as indicated in the name, are there barlines. Even the provided information can be puzzling at first: a series of whole notes, vaguely connected by a number of slur-like markings, spaced at varying distances from one another and occasionally marked with ornamentation.

By examining historical evidence from contemporaries -- including treatises on performance practise and examples of unmeasured preludes from other French Baroque composers -- and synthesising these with a modern understanding of harmony and structure, this paper attempts to remain true to the composer's original intent while exploring various methods of interpreting these preludes, in order to make these works accessible to a wider selection of performers and researchers.