Bartok - 44 Duos Volume 2 #26-44 - Two Violins Universal UE10452B
Volume 2 includes 19 moderately difficult songs and dances of Eastern European folk music (pieces 26-44) Each of these duos – with the two indicated exceptions – incorporates a peasant melody as the principal theme. The studies have been compiled in order of difficulty to enable the player to gauge his or her progress.
At a recital, naturally, this order should not be maintained; it would be more to the point if the pieces selected for performance were arranged into one or more (related) series and the pieces within each series played 'attaca'. The edition includes examples of such grouping arrangements.