Ben Keith, a steel guitarist and multi-instrumentalist who played for 40 years with Neil Young, has died. He was 73.

Keith died of a heart attack at Young's California ranch, according to Jonathan Demme, who has directed Young's concert films.

Keith had recently been touring with Young's wife Pegi in support of her album Foul Deeds and working with Young on a new project.

He had worked with Young since 1971 and played on more than a dozen recordings, including Harvest, Comes a Time, Harvest Moon and Greendale.

Young dedicated the song Old Man to his long-time collaborator at a show in Winnipeg on Monday.

"This is for Ben Keith. His spirit will live on. The earth has taken him," he said.

Keith had played with Bob Dylan, Ringo Starr, Linda Ronstadt, Willie Nelson and dozens of other artists in a career dating back to the late 1950s.

A session musician in Nashville, Keith played steel guitar on Patsy Cline's 1961 hit I Fall to Pieces and worked with many other country artists including Johnny Cash.

He is credited with helping Young develop his signature sound on the album Harvest and especially on the song Old Man.

He'd come into the studio as a session musician and didn't know Young when they started playing together in 1971.

In a 2005 interview, Young remembered that session.

"Ben and I developed the style during those sessions. When we did Old Man and talked about what he could play, I said 'Try to play those single notes and make it sound doubled. Just ride those babies all the way through there, that's a great sound,'" Young said.

Keith went on to play with Crosby, Stills and Nash and secured a spot in Young's band when he went solo.

He played many other instruments, as well as steel guitar, and his versatility is seen in Neil Young Trunk Show, Demme's documentary about Young's 2007-08 concert tour.

He also had a small role in Young's stage production of concept album Greendale as Grandpa Green.

Keith made his solo debut in 1984, playing alongside J.J. Cale and Paul Butterfield on To a Wild Rose, and released Seven Gates: A Christmas Album in 1994.

He also produced Jewel's debut album, Pieces of You, which launched her career, according to allmusic.com.

With files from The Associated Press