Originally from Cenoví, a town outside of San Francisco de Macorís, Santos' career spans over forty years.
Since he performed mostly in country social clubs and for patron saints' festivals, he was not marginalized as were many of his fellow bachateros.
Santos' style was much simpler and more straightforward than that of other guitarists such as Edilio Paredes; it was also rhythmic and danceable.
his sister Leonilda Alejo moved to the United States and made some very popular songs such as Mamita and sera porque soy pobre.
[1] Santos is specially remembered because he developed an innovative way to perform the merengue with guitars, in opposition to the traditional way of the conjunto tipico or the combos (another popular urban style of orchestra).