From a technical point of view, instrumental music mak-ing involves audible, visible and hidden playing parameters. Hidden parameters like force, pressure and fast movements, happening within milliseconds are particularly difficult to capture. Here, we present data focusing on movement coordination parameters of the left hand fingers with the bow hand in violinists and between two violinists in group playing. Data was recorded with different position sensors, a micro camcorder fixed on a violin and an acceleration sensor placed on the bow. Sensor measurements were obtained at a high sampling rate, gathering the data with a small mi-crocontroller unit, connected with a laptop computer. To capture bow's position, rotation and angle directly on the bow to string contact point, the micro camcorder was fixed near the bridge. Main focuses of interest were the changes of the left hand finger, the temporal synchronization between left hand fingers with the right hand, the close up view to the bow to string contact point and the contact of the left hand finger and/or string to the fingerboard. Seven violinists, from beginners to master class students played scales in different rhythms, speeds and bowings and music excerpts of free choice while being recorded. One measure-ment with 2 violinists was made to see the time differences between two musicians while playing together. For simple integration of a conventional violin into electronic music environments, left hand sensor data were exemplary converted to MIDI and OSC.