A rotor of a turbomachine includes a plurality of rotor blades, which each have a blade leading edge and a tip, the rotor blades forming a first group and at least one further group of rotor blades of different construction. It is provided that the rotor blades of the first group are nominal rotor blades, the rotor blades of the at least one further group each have a material cutout in the transition from the blade leading edge to the tip, the material cutout not being present in the case of the rotor blades of the first group, and the rotor blades of the first group and of the at least one further group form a non-periodic sequence in a circumferential direction.