In addition to work in the studio and on-stage playing with PJ Harvey, Beck, Gnarls Barkley, Warpaint, and more, Klinghoffer spent the years between 2009 and 2019 actively as lead guitar player with Red Hot Chili Peppers. During this time, he stayed busy with projects like the more experimental Dot Hacker, as well as a plethora of special appearances, one-off gigs, and studio work. Klinghoffer began to work on the material for Pluralone in 2018 and continued with sporadic recording sessions into 2019. The first official release from the project came in August of that year, as a single that included two cover songs. Klinghoffer chose two songs not sung in English: Italian singer Mina's "Io Sono Quel Che Sono" and Jorge Ben's "Menina Mulher da Pele Preta." He continued working on his proper album, with help from Flea, former Jane's Addiction member Eric Avery, and many other collaborators. Titled To Be One with You, the record was released in November 2019. Its textural and at times experimental rock songs tapped into the influence of artists ranging from John Cale to Jeff Buckley.
In December 2019, Klinghoffer officially parted ways with Red Hot Chili Peppers, and his friend, collaborator, and noted ex-Chili Pepper John Frusciante, returned to the band. The second Pluralone album, I Don't Feel Well, quickly materialized and was released in December 2020. In the years that followed, Klinghoffer joined both Pearl Jam and Eddie Vedder's solo offshoot band Earthlings, and continued appearing on tracks from artists like Cate Le Bon, Adam Levine, and Elton John. In 2022, Klinghoffer released This Is the Show, the third LP under the Pluralone banner. This time around, he was joined by Avery on a few tracks, as well as drummer Eric Gardner and cellist Vanessa Freebairn-Smith. ~ Fred Thomas, Rovi