Diesel Harmonics (a mechanical engineering term for fine-tuning diesel motors) was David's concept for a five-guitar band. He used this idea to orchestrate each guitar part, blending to make a singular smooth sound. He recorded his first solo album, "Diesel Harmonics" in 1993 (co-produced with Stephen Jarvis) with Prairie Prince, Anders Rundblad (Wire Train, Cheryl Crow), and himself on all 5 guitar parts. The Live Diesel Harmonics band, a Fender guitar onslaught, was David, Dave Shul, Larry Trott, Gary Arago, Happy Sanchez, Jim Gordon and David's son, Mason Denny sitting in on a few gigs.