Orion was founded in 1992 by musicians Kathryne Pirtle (clarinet), Florentina Ramniceanu (violin) and Diana Schmück (piano) as a performing and presenting ensemble. Musicians Judy Stone (cello) and Jennifer Marlas (viola) joined the Ensemble subsequently, creating a core of five musicians recognized as a major artistic force in chamber music.

The Orion Ensemble achieved 501(c)(3) status in 1993 as it embarked upon its first publicized concert series. Beginning that season, Orion has performed several times annually in live national broadcasts on WFMT-FM. Together with Norm Pellegrini, former director of WFMT, Orion helped to keep the live WFMT series from dissolving early on by finding a funding source for the live broadcast. Orion also regularly performs at Chicago Cultural Center concerts. Through the years, the Ensemble has continually performed premieres of new works, invited collaborations with other artists and sought opportunities for outreach to share its music with new audiences. Upon Orion’s 10th anniversary in 2002, Kathryne Pirtle recalled the Ensemble’s founding years for Joe O’Brien in an article for Network Chicago, stating, “In my mind, I envisioned a group that would be permanent, that would last hopefully for the rest of my life.”

Orion has presented a four-concert subscription series in Chicago and its suburbs since 1993. In its premiere year (1993–1994), Orion Chamber Ensemble began its subscription series in Chicago at the National Shrine of St. Francis Xavier Cabrini and at Fox Valley Unity Church in Batavia, Illinois. During this first season, Orion had musicians Adam Smyla (viola) and Michael Masters (cello) on its roster, in addition to the founders: Kathryne Pirtle (clarinet), Florentina Ramniceanu (violin) and Diana Schmück (piano).

For the second and third seasons, the Chicago venue moved to the Near North Side’s historic Three Arts Club. During this time, the three founding musicians continued the series, using guest violists and cellists to round out the ensemble. Of note was the addition of a young violinist, Rachel Barton (Pine), before she embarked on her successful solo career. Frank Babbit was principal violist for the third season, and current core musician Judy Stone performed her first concerts with Orion as a guest cellist.

In 1996, with the fourth season and the beginning of its residency, Orion moved its Chicago series to Ganz Hall of the Chicago College of Performing Arts at Roosevelt University. That same year, Judy Stone (cello) and Marlise Klein (viola) were invited to join the ensemble, creating the first enduring core of five musicians.

Orion added a third venue to its annual series in 2001, with Winnetka Presbyterian Church hosting the Sunday afternoon concerts. Marlise Klein played her last year with Orion in 2004–2005 before moving from the Chicago area. In 2005, concerts relocated to the Music Institute of Chicago’s Nichols Hall in Evanston. The addition of the considerable talents of Jennifer Marlas (viola) occurred during the 2005–2006 season.

The Ensemble’s west suburban venue in Batavia remained at the Fox Valley Unity Church for 14 years before moving in 2007 to the Fox Valley Presbyterian Church in Geneva. The current series continues with four concerts every season at each of the three venues (Ganz Hall, Nichols Hall and Fox Valley Presbyterian Church) and with five outstanding musicians: Kathryne Pirtle (clarinet), Florentina Ramniceanu (violin), Diana Schmück (piano), Judy Stone (cello) and Jennifer Marlas (viola).