The link between musicians and dancers is generally described as strong in many traditional musics and this holds also for Scandinavian Folk Music - spelmansmusik. Understanding this interaction has potential for developing theories on performance strategies that can be useful for artistic and pedagogical purposes. This serves the aim of the ongoing doctoral project “Oral Music Theory – music theoretical tools for performance expression within folk music” conducted in collaboration between KMH Royal College of Music and KTH Royal Institute of Technology. Motion capture data of live performances of three fiddlers and two dancers were recorded, as well as dancing of the same dancers to recordings by an influential player. A first paper incorporated measurements and visualizations of performance data, contextualized by interviews with the performers. A second study further investigated the link between dancer and musician by having the same musicians perform to animations generated from the motion capture recordings of the dancers. The different stimuli focused on motions of selected body parts with the aim to understand how different movements can provide reliable cues for musicians. Results illustrate a reliable alignment to renderings showing full skeletons of dancers, and an advantage of focused displays of movements in the upper back of the dancer. Based on these results, we currently explore how asymmetric beat patterns relate to melodic rhythmic surface structures in Swedish local polska traditions. Our paper will summarize our previous results, introduce the collected data, and provide first results from this current work. Examples of results include the relation of onset frequency and rhythmic gestalt to relative beat duration.