The clip above is from Dj Pj-roc Reacts, a hip-hop Dj's exploration and appreciation of country music. It includes audio, with photo montages, of what is considered Gram Parsons' signature song, "Hickory Wind." It begins, following some commentary, with a version from late in his career that he sang with Emmylou Harris. Here's a link to a clip, audio only, of the original 1968 version from Gram's brief time with the Byrds, in which he appeared on their album Sweetheart of the Rodeo.
Today's New York Times has this story by Lindsay Zoladz, in which she argues for a new focus on Gram's role as, if you'll pardon my use of a fashionable buzz-word, a disruptor. She quotes Gram's friend, Keith Richards, in his autobiography, written with James Fox, Life, that Gram "changed the face of country music, and he wasn't around long enough to find out."
Addendum: before her story linked above was published in the Times, Lindsay Zoladz had a piece in the paper's "Amplifier" column, The Legend of Gram Parsons in 12 Songs in which she links to videos of performances of his songs she considers most memorable. Ten of them feature Gram on vocal and guitar, either solo or with groups he was in: the International Submarine Band, the Byrds, and the Flying Burrito Brothers, in chronological order. One is by Elvis Costello: "I'm Your Toy," his re-titled cover of "Hot Burrito #2"; the other is Emmylou Harris' heart wrenching version of "Boulder to Birmingham."
While Gram was still in high school he played in several rock bands and later in an acoustic folk group, the Shilohs. His stepfather, Bob Parsons, opened a "teen age night club" called the Derry Down in downtown Winter Haven, in large part to provide a venue for Gram and his groups to perform. In 2016 I attended the grand re-opening of the Derry Down, featuring a Cosmic American Music Festival. "Cosmic American Music" was what Gram called his style, which combined elements of country. rock, blues, and soul.