He became a successful session player on recordings by artists including Roy Orbison, Al Hirt, Henry Mancini, Dan Fogelberg, Linda Ronstadt, J. J. Cale, Tony Joe White, the Nitty Gritty Dirt Band, the Byrds, Michael Card, Ian & Sylvia and Bobby Goldsboro.

In this role, he is credited with broadening Nashville as a recording center by bringing in non-country acts such as Jimmy Buffett, Joan Baez and Dan Fogelberg.

[5] After a couple of years they were hired by Tom Stafford, Rick Hall and Billy Sherrill to make demo recordings for a publishing company.

Putnam and his bandmates later followed Rick Hall to work at FAME Studios in Muscle Shoals and served as the rhythm section for hit records by Arthur Alexander, Tommy Roe and The Tams.

His credits include works that established the popularity of performers such as Jimmy Buffett, Buffy Sainte-Marie, Joan Baez, Dan Fogelberg, Michael Card, Brewer & Shipley, Pousette Dart Band, Donovan, John Hiatt, J.J. Cale, the Flying Burrito Brothers, John Stewart and the New Riders of the Purple Sage.

[5]: 153  Putnam made technical innovations and newer equipment to improve recording quality and is credited with creating a wave of modernization of many Nashville studios.