[1] Jethro was born in Vancouver into a musical family, and began studies on the violin as a child.
He made his solo debut at the age of 17 with the Loudoun Symphony in Virginia, performing Mendelssohn's Violin Concerto.
As a chamber musician, Marks has performed at prestigious festivals around the world including Ravinia, Aspen, Tanglewood, Santa Fe, Mostly Mozart, and the BBC Proms.
[1] With the Zukerman Chamber Players he has performed over 40 concerts around the world and recorded two CDs since 2003.
In January 2007, Marks performed the World Premiere of Steven Gellman's Viola Concerto with the Ottawa Symphony Orchestra to critical acclaim.