The harmony search (HS) is a music-inspired evolutionary algorithm, mimicking the improvisation process of music players (Geem et al., 2001). The HS is simple in concept, few in parameters, and easy in implementation, with theoretical background of stochastic derivative (Geem, 2007a). The algorithm was originally developed for discrete optimization and later expanded for continuous optimization (Lee & Geem, 2005). The following pseudo code describes how the HS algorithm works: procedure HS // initialize initiate parameters initialize the harmony memory //main loop while (not_termination) for I = 1 to number of decision variables (N) do R1 = uniform random number between 0 and 1 if (R1 < P