Music-inspired harmony search algorithm is a recently developed metaheuristic technique. It has been extensively used in the development of structural optimization algorithms. Several enhancements are suggested to standard harmony search method. In this paper, firstly these improvements are summarized and later they are used to determine the optimum design of three dimensional steel frames. The design constraints are implemented according to LRFD-AISC (Load and Resistance Factor Design-American Institute of Steel Corporation) in the formulation of the optimization problem. The minimum weight is taken as objective function. Two design examples are considered to evaluate the performance of seven different versions of harmony search algorithm.