A bladed rotor system for a turbomachine, comprising: a circumferential row of blades mounted on a rotor disc, each blade comprising: an airfoil extending span-wise along a radial direction from a root portion to an airfoil tip; and a circumferentially extending snubber attached to the airfoil at a mid-span region of the airfoil, wherein in operation, snubbers of adjacent blades abut circumferentially, wherein the row of blades comprises a first set of blades and a second set of blades, wherein the blades of the second set are distinguished from the blades of the first set by a geometry of the snubber that is unique to the respective set (H, L), in which: the snubbers of the second set are attached to the respective airfoils at a different span-wise height than that of the snubbers of the first set, whereby the natural frequency of a blade in the second set differs from the natural frequency of a blade in the first set by a predetermined amount, wherein blades of the first set and the second set are positioned alternately in the row of blades, to provide a frequency mistuning to stabilize flutter of the blades, wherein a free length (r e2) of the airfoils in the second set is larger than a free length (r e1) of the airfoils in the first set, the free length (r e1, r e2) of an airfoil being defined as a radial distance between the airfoil tip and a point of attachment of the airfoil with the associated snubber, wherein each snubber comprises a pressure side snubber portion extending from a pressure side of the respective airfoil and a suction side snubber portion extending from a suction side of the respective airfoil, wherein the pressure side snubber portion and the suction side snubber portion of the snubbers in the second set are oriented differently than the pressure side snubber portion and the suction side snubber portion of the snubbers in the first set, such that snubbers of adjacent blades of the row of blades meet at a constant radial height (r r), and characterised in that the pressure side snubber portion and the suction side snubber portion of each snubber in the first set extends radially inwardly from said point of attachment, and the pressure side snubber portion and the suction side snubber portion of each snubber in the second set extends radially outwardly from said point of attachment. a circumferential row of blades mounted on a rotor disc, each blade comprising: an airfoil extending span-wise along a radial direction from a root portion to an airfoil tip; and a circumferentially extending snubber attached to the airfoil at a mid-span region of the airfoil, wherein in operation, snubbers of adjacent blades abut circumferentially, an airfoil extending span-wise along a radial direction from a root portion to an airfoil tip; and a circumferentially extending snubber attached to the airfoil at a mid-span region of the airfoil, wherein in operation, snubbers of adjacent blades abut circumferentially, wherein the row of blades comprises a first set of blades and a second set of blades, wherein the blades of the second set are distinguished from the blades of the first set by a geometry of the snubber that is unique to the respective set (H, L), in which: the snubbers of the second set are attached to the respective airfoils at a different span-wise height than that of the snubbers of the first set, whereby the natural frequency of a blade in the second set differs from the natural frequency of a blade in the first set by a predetermined amount, wherein blades of the first set and the second set are positioned alternately in the row of blades, to provide a frequency mistuning to stabilize flutter of the blades, wherein a free length (r e2) of the airfoils in the second set is larger than a free length (r e1) of the airfoils in the first set, the free length (r e1, r e2) of an airfoil being defined as a radial distance between the airfoil tip and a point of attachment of the airfoil with the associated snubber, wherein each snubber comprises a pressure side snubber portion extending from a pressure side of the respective airfoil and a suction side snubber portion extending from a suction side of the respective airfoil, wherein the pressure side snubber portion and the suction side snubber portion of the snubbers in the second set are oriented differently than the pressure side snubber portion and the suction side snubber portion of the snubbers in the first set, such that snubbers of adjacent blades of the row of blades meet at a constant radial height (r r), and characterised in that the pressure side snubber portion and the suction side snubber portion of each snubber in the first set extends radially inwardly from said point of attachment, and the pressure side snubber portion and the suction side snubber portion of each snubber in the second set extends radially outwardly from said point of attachment.