German violinist and conductor Petra Müllejans co-founded and has been a central creative force in the development of the Freiburger Barockorchester historical-performance ensemble. Müllejans was born in Düsseldorf, Germany, in 1959, and grew up in the nearby community of Meerbusch, attending the new Meerbusch Gymnasium high school. Although she recalled that her school career was not entirely "praiseworthy," she became part of the school's first graduating class at age 17. She studied the violin from age five as well in Meerbusch and won admittance to the Musikhochschule in Düsseldorf, where one of her teachers was the violinist and musicologist Helga Thoene. Her historical interests intensified after she moved, at 21, to the Hochschule für Musik in Freiburg to study with Rainer Kussmaul. She was also influenced by his brother, violist Jürgen Kussmaul, and she switched to Baroque violin. Early in her career she worked with conductor Nikolaus Harnoncourt in Vienna.

A final major influence was the Baroque violinist Gottfried von der Goltz, who is also the father of Müllejans' two children. The pair co-founded the Freiburger Barockorchester (Freiburg Baroque Orchestra) in 1987, and later the ancillary Freiburg Baroque Consort. The arrangement was unusually flexible, for either Müllejans or von der Goltz could serve as violin soloist, conductor, or both, in the case of the Freiburger Barockorchester 2018 recording of Handel's Concerti a duo cori. Müllejans has amassed a large catalog of critically acclaimed recordings with the orchestra, both with and without von der Goltz. She conducted the orchestra in a highly experimental recording of Mozart's K. 453 and K. 482 piano concertos with keyboardist Kristian Bezuidenhout.

Müllejans is professor of Baroque violin at the Hochschule für Musik in Frankfurt am Main. She also performs still more experimental forms of Baroque music with the Americo-German musical-marital duo of keyboardist Hille Perl and lutenist Lee Santana, and she is a member of klezmer and jazz ensembles. ~ James Manheim, Rovi