A fanfic written a year ago. This is headcanon.
When he was her age, he knew organ and viol. Then he studies how Sabine reaches out to the wisps with his memory of his preference of electric instruments, such as the red ball jet keyboard and the quetarra guitar
Thrawn as a child before 7 years old played the organ – a call to the trope of Bach’s Toccata. And the viol. He could play it, but did not like it. But he always wanted to play the jet keyboard or the quetarra guitar.