Mid-1960s, he first played in some locally well-known bands such as The Kingbees and The Flying Machine. In the latter he first met James Taylor. In 1967, he then joined the Fugs, until he left the band along with bassist Charles Larkey and moved to California. Along with Carole King founded the two came to The City. However, the band split up in 1969 after only one album again. Kortchmar now worked as a session musician, he played 1970 to James Taylor's Sweet Baby James and Mud Slide Slim 1971 Taylors and the Blue Horizon and Carole King's Tapestry.
In 1973, Kortchmar his solo debut Kootch on the market. Only in 1980 was followed by Innuendo. Otherwise, Kortchmar operated in this period continued as a studio musician, for example, Linda Ronstadt, Jackson Browne, Warren Zevon and Harry Nilsson. In 1982, he co-wrote some of the songs of Don Henley's solo debut I Can not Stand Still, under these Dirty Laundry. In the 1980s, Kortchmar first began to produce albums, including that of Neil Young, Billy Joel, Toto and Jon Bon Jovi.
The mid-1990s Kortchmar now produced albums by the Spin Doctors and Freedy Johnston. He also joined briefly at the Fabulous Thunderbirds.
He is co-author of 2012 published by Joe Bonamassa songs Driving Towards The Daylight.