A native of Seattle, Washington, Overall’s work is best described by City Arts as bridging “Coltrane-esque spiritual-quest jazz, Brainfeeder Records’ trendsetting cosmic beat science, Shabazz Palaces’ Afrofuturist art rap and his own special brand of unpredictable, alluring weirdness.” Aside from his own work, Kassa has performed with a formidable list of extremely varied artists, including Yoko Ono, Christian McBride, Vijay Iyer, Dee Dee Bridgewater, Terri Lyne Carrington, Geri Allen, Francis & the Lights, Marc Ribot, Mayer Hawthorne, Ravi Coltrane, Gary Bartz, and many more. He spent several years as a key member of pianist Geri Allen's Timeline band and spent close to a decade touring and recording with trumpeter Theo Croker (whose Escape Velocity he co-produced). As a rapper and producer, Overall has collaborated with the hip-hop outfit Das Racist. In 2017, he was part of The Late Show with Stephen Colbert's house band, Jon Batiste & Stay Human.