His musical training began at the age of seven with classical piano lessons encouraged by his mother, Mary O'Brien, a silent film actress. O'Brien's roles including the wife in Buster Keaton's 1926 movie Battling Butler.
At age seven, he started learning music with classical piano lessons, motivated by his mother, Mary O'Brien, who was involved in silent films. O'Brien played the role of the wife in Buster Keaton's 1926 film Battling Butler.