 Rosenthal was the winner of the Thelonious Monk International Jazz Competition in 1988, which launched his career as a solo artist, leading to the release of his first CD as a leader "New Tunes, New Traditions", featuring Ron Carter, Billy Higgins and Tom Harrell; the album interweaves Thelonious Monk's with Rosenthal's original compositions.Rosenthal toured in the early 1990s with the last Gerry Mulligan Quartet, recording three CDs with Mulligan and performed in major jazz festivals throughout the world.One critic noted, "The rapport of the [Mulligan] group was amazing, particularly Gerry’s telepathic communication with outstanding pianist Ted Rosenthal [...] The byplay with Rosenthal left me with my jaw hanging down" (Gene Lees, "The Jazz Letter").