The following artists are people Greg has studied or performed with:
John Abercrombie
Bill Beach
Overton Berry
Johnny Butler
John Cage
Jason Carter
Scott Cossu
Jorgen Cruise
Barbara Donald
Herb Ellis
Essiet Okon Essiet
Ron Green
Billy Haddon
Horace Henderson
Holy Modal Rounders
Don Lanphere
Ike Levin
Sam LiPuma
Brett Lucich
Robert Moran
Tom Newman
Paul Painter
Les Paul
Pete Karnes Blues Band
Steven Ridley
Howard Roberts
Dianne Schuur
Kevin Selfe
Charlie Teske
Jay Thomas
Mel Torme
Ted Trimble
Danny Wold