Ethel was founded in 1998 by violinists Todd Reynolds and Mary Rowell, violist Ralph Farris, and cellist Dorothy Lawson. In 2005, violinist Cornelius Dufallo, who had been a member of the Flux Quartet, replaced Todd Reynolds, and Jennifer Choi, formerly of the Miró Quartet, replaced Mary Rowell in 2011. All of the group's founding and current members had studied at Juilliard. Collaboration is a foundational principal on which Ethel operates, whether with composers and choreographers, classical performers like Ursula Oppens, Colin Currie, and Iva Bittová, as well as ensembles Bang on a Can, Ensemble Modern, and Lionheart, or rock musicians such as Todd Rundgren, David Byrne, Joe Jackson, and Kurt Elling. The long list of composers with whom the group has worked includes John Zorn, Phil Kline, Julia Wolfe, Osvaldo Gólijov, John King, Pamela Z, Don Byron, David Lang, Kenji Bunch, Randall Woolf, Judd Greenstein, and Marcelo Zarvos. Ethel has collaborated with choreographer Annie-B Parson and with the Dusan Tynek Dance Company. A significant aspect of its collaborative initiative and commitment to outreach is its ongoing involvement with the Native American Composer Apprenticeship Program as Ensemble-in-Residence at the Grand Canyon Music Festival, where it nurtures and performs the work of young Native American composers.
The quartet regularly performs with amplification and is dedicated to exploring the use of emerging technologies. It has been involved at Rensselaer Polytechnic Institute, Experimental Media and Performing Arts Center in Urbana, IL, and the Technology, Entertainment, Design (TED) Conference, where it was the house band in 2010.
Ethel has performed on several dozen recordings by other artists and is featured artist on a number of albums, including Phil Kline's John the Revelator, Julia Wolfe's String Quartets, Mary Ellen Childs' Dream House, Neil Rolnick's Extended Family, and John King's AllSteel. The quartet has released three solo albums, ETHEL (2003), Light (2006), and Heavy (2012).