Harmony Search Algorithm: A Unique Music-inspired Algorithm

Since the Harmony Search Algorithm (HSA) was first introduced in 2001, it has drawn a world-wide attention mainly because of its balanced combination of exploration and exploitation and ease of application. The HSA, inspired by musical performance process, consists of three operators: random search, harmony memory considering rule, and pitch adjusting rule. The ways of handling exploration and exploitation with the three operators make the HSA a unique metaheuristic algorithm. However, a series of papers was recently published by an author which insisted that the HSA is equivalent to an evolution strategy (ES). The ES, based on ideas of adaptation and evolution, consists of two operators: recombination and mutation operators. Except the similarity in generating a single new solution at each iteration which can replace the worst solution in the population, other components (e.g., their exploration and exploitation strategies and structure) are totally different between the HSA and ES. This paper is written to rebut and point out academic flaws in the papers.