Lysy was born in 1935 in Buenos Aires and began playing the violin when he was five years old, initially learning from his father. Around 1948, he quit school so he could spend more time with the violin, and he started studying with Ljerko Spiller. Four years later, the 17-year-old traveled to London, where he attended the Silver School. He supported himself by working as a street performer, playing his violin under a bridge near the Royal National Theatre. In 1955, he became the first South American to win an award in the Queen Elisabeth International Music Competition. One of the jurors at the competition was Yehudi Menuhin, whom Lysy approached and expressed that he wanted to learn from the master violinist. Menuhin eventually accepted Lysy as his first and only student, and Lysy moved to Menuhin's home in Gstaad, Switzerland. They gave the premiere performance of Malcolm Arnold's Concerto for two violins in 1962 and continued performing together until the mid-'60s.
In 1965, Lysy founded the Camerata Bariloche chamber ensemble, and he conducted their first concert in 1967. He also established the Camerata Lysy chamber ensemble in 1971, intended for his more advanced students. Lysy led both groups on several tours throughout the world, and they performed with many of the top conductors including Pierre Boulez, Adrian Boult, and Colin Davis. In honor of his friend and mentor, Lysy created the International Menuhin Music Academy in 1977. He continued conducting and traveling with his chamber ensembles through the 1980s.
As a violinist, he collaborated on recordings with Sandor Végh, Luisa Majone, and Aquiles Delle-Vigne. He also recorded Kodaly's Duo for Violin and Cello in 2001 with his son, cellist Antonio Lysy. In 2006, he was recognized for his work with the IMMA and was presented with the Stradivari International Pedagogical Prize. Lysy retired the following year and passed away in Lausanne, Switzerland, on December 30, 2009. ~ RJ Lambert, Rovi