greek week???

Team Rolling Stones à Alpha Delta Pi, Phi Delta Theta, Kappa Alpha Psi, Lambda Theta Phi
Team Aerosmith à Kappa Kappa Gamma, Delta Chi, Alpha Kappa Alpha
Team Guns and Roses à Chi Omega, Alpha Gamma Rho, Delta Tau Delta
Team ACDC à Gamma Phi Beta, Kappa Sigma, Chi Psi, Sigma Gamma Rho
Team Led Zeppelin à Zeta Tau Alpha, Phi Sigma Kappa, Zeta Phi Beta, Tau Kappa Epsilon
Team Pearl Jam à Kappa Delta, Beta Theta Pi, Triangle, Phi Beta Sigma
Team Queen à Delta Delta Delta, Alpha Tau Omega, Alpha Phi Alpha
Team Red Hot Chili Peppers à Alpha Chi Omega, Lambda Chi Alpha , Delta Sigma Theta
Team KISS à Kappa Alpha Theta, Alpha Sigma Pi, Phi Gamma Delta, Beta Upsilon Chi
Team Beatles à Sigma Kappa, Pi Kappa Phi, Omega Psi Phi, Sigma Iota Alpha
Team Pink Floyd à Delta Zeta, Kappa Alpha Order
Team Eagles à Alpha Phi, Sigma Nu, Farm House

How do the pairings for Greek Week get chosen?