His fascinating live shows feature him solo on-stage with a Gibson Echoplex Digital Pro looping unit, and he creates his backing loops in the moment, building and improvising as he goes on his custom-made ten-string guitar, and thanks to his equally as quirky, upbeat, and semi-surreal songs (which he frequently weaves into extended, half-improvised medleys) and his warm, friendly tenor singing voice, Williams is an utterly unique performer whose musical eccentricities don't keep him from being immediately accessible. A native of Virginia, Williams received his first guitar at the age of three, although he admits he didn't really learn to play it until he was in his early teens. He attended high school in his hometown of Fredericksburg, and began playing solo gigs when he was 17. He discovered the new age guitar genius of Michael Hedges a year or so later, and Hedges has been a lifelong influence on Williams' approach to the guitar.

Following a stint at college (he attended Virginia Wesleyan College in Virginia Beach from 1988 to 1991, majoring in theater) and frequent gigs in his hometown region, he self-released a debut album, Freek, in 1994. Williams relocated to Colorado the following year, and it was there where he met the members of the progressive bluegrass band String Cheese Incident at the Telluride Bluegrass Festival. Williams ended up touring with them as an opening act in 1997 and again in 1998. A second solo album, Buzz, was released in 1996. Williams eventually signed to String Cheese Incident's label, SCI Fidelity, and released Spun in 1998.

Incredibly prolific, Williams has released nearly an album a year ever since on SCI, all with one-word titles. Breathe appeared in 1999, Loop in 2001, Laugh in 2002, Dance and Home in 2003, Stage in 2004, and the DVD Sight in 2005. Grass (credited to Keller & the Keels) appeared in 2006 and Dream in 2007. In December of 2007 he released his 12th CD, a compilation appropriately titled 12. Odd arrived in 2009, followed in 2010 by Thief (with the Keels) and Kids, the latter of which represented Keller's first official foray into children's music. Bass was released in 2011, followed in 2012 by Pick, a collaboration with the Travelin' McCourys. Endlessly creative, innovative, and fun, Williams is a fascinating artist, and his somewhat wacky take on the world and his amazing and eccentric guitar talents make him a refreshing performer. ~ Steve Leggett