Polo Urías is a norteño singer who played bajo sexto from Ojinaga, Chihuahua Mexico.He was A head singer of Los Rieleros del Norte,until a fight broke out in 1994, So he left Los Rieleros del Norte,And formed his own band, Polo Urías y su Maquina Norteña.Some of his most popular hits are Veinte Años, Una Aventura, and Mi Primer Amor.