Kohler was born in Shelby, Montana to John, a respected educator and musician, and Marjorie, a well regarded church organist. Raised in Great Falls, MT, Kohler often performed music with his parents and siblings in his youth. After graduating from Great Falls High School and briefly attending college in Boise, Idaho, Kohler moved to Bozeman, MT, where he was a founding member of the band In Flight with his older brother Lee Kohler and their friend Robi Johns. In 1987, Rob met Jill Bergene, another Great Falls native, in Bozeman and had two daughters, Maja and Wesley. In 1995, Rob and Michelle Warner, of McMinnville, OR, were married in Bozeman and had a son, Samuel.
Music career
In Flight grew popular in Montana and performed at the Montreux Jazz Festival in Switzerland in 1987. After disbanding in 1990, Lee and Rob reformed the group in 1995 under the name This World. They produced an eponymous album in 1996 with Cookie Marenco, a Grammy award-winning producer. During this time, Kohler performed extensively at the Vancouver International Jazz Festival, the Bozeman Bass Bash, and the Strawberry Festival. Kohler has also recorded and performed extensively with Oregon-based Folk singerAlice Di Micele. Kohler's work with his band Spirit Session was reviewed by CADENCE Magazine, a nationally renowned Jazz publication, in 2006. Currently, Kohler is based in Los Angeles, and performs regularly with Winston Raval and the Vanishing Tribe, a band that fuses Jazz with Traditional Filipino music, and The Honorifics, a Las Vegas-based rock band. The Honorifics have won multiple Indie Music Channel Awards and have been featured in Indie Rock Magazine.
Teaching
Kohler began teaching at the Stanford Jazz Workshop in 1991, playing with Ravi Coltrane in his first year. During his time at Stanford, Kohler has performed and taught artists such as Julian Lage, Taylor Eigsti, John Stowell, Ambrose Akinmusire, Fabian Almazan, Anton Schwartz, and Charles Altura. He was education director at SJW from 2006–2007. Kohler also taught at NOCCA in New Orleans, Louisiana, implementing a Middle School Jazz program there that lasted until 2009. He has been an instructor at the annual in Ladner, BC since 2003. In 2013, Kohler wrote and published a text book on Beginner Jazz Theory, entitled Music Theory from A to G, which is published by Kohler Music Publishing, a company run by Kohler's sister Kate Kohler. He is also working on a series of Bass Instructional Youtube videos.