 At seven, he gave his first violin concert with the Guatemalan military band/orchestra (the only musical ensemble during the dictatorships of that time).During his childhood and adolescence, Andrés studied violin with the most prominent musicians in Guatemala, many of whom were Italian or German expatriates from the late 1800s, and assumed principal positions in the military band/orchestra and conservatory.Since the age of ten he performed and earned a sustainable living playing at church functions, weddings, assembling chamber players for private functions, and even assembling orchestra players for "pit" background music to silent movies at the "Teatro Lux".