During and for a brief time after his college days, Graydon played in the Don Ellis Band, whose style can be described as experimental post-bop jazz.

From the late 1960s to late 1970s Graydon was a session musician in Los Angeles, working with such artists as Gino Vannelli, Barbra Streisand, Dolly Parton, Diana Ross, The Jackson Five, Alice Cooper, Cheap Trick, Al Jarreau, Christopher Cross, Ray Charles, Cher, Joe Cocker, Marvin Gaye, Hall & Oates, Wayne Shorter, Olivia Newton-John, Albert King and Steely Dan.

Jay Graydon's production credits include work with Airplay, Air Supply, George Benson, Al Jarreau, DeBarge, El DeBarge, Sheena Easton, Art Garfunkel, The Manhattan Transfer, Johnny Mathis, Patti LaBelle, Lou Rawls, Dionne Warwick, Alan Sorrenti and the album They Don't Make Them Like They Used To by Kenny Rogers.

His catalog includes the Grammy winners "Turn Your Love Around" (co-written with Steve Lukather and Bill Champlin) as performed by George Benson and "After the Love Has Gone" (co-written with David Foster and Bill Champlin) as performed by Earth, Wind & Fire, as well as "Who's Holding Donna Now" (DeBarge), "Friends in Love" (Dionne Warwick and Johnny Mathis), many songs written with and for Al Jarreau (including "Mornin'", "Breakin' Away", "High Crime", "After All", and "Roof Garden"), and several hits with Manhattan Transfer including "Twilight Zone", "On The Boulevard", "Smile Again" and "Spies in the Night".

Graydon has written numerous articles in music magazines, and has conducted seminars at Musician's Institute in Hollywood with guitarist Tommy Tedesco for more than 15 years.

Graydon has participated as a musician and/or songwriter in over 50 film scores including The French Connection, Grease, Ghostbusters, St. Elmo's Fire, The Secret of My Success, Navy Seals, Lady Sings the Blues, The Greatest, Ghost Dad, Mahogany, and Thank God It's Friday.

Foster and Graydon have worked together on several album projects, including the band Airplay, a pop-rock group they formed in the late 1970s, and the JT Super Producer concert in Japan in 1994 with René Angélil and Céline Dion.