Rojahn was awarded the Roger Sessions Award for composition upon graduation from the Boston Conservatory with a Master of Music in Composition in 2004. His music has been featured at the Boston Conservatory's New Music Week. He has been the Composer-in-Residence for the Ludovico Ensemble since 2005. Commissions include the Quincy Symphony Orchestra under Yoichi Udagawa and the Arbelos Piano Trio. His song cycle Lust based on the novel by Elfriede Jelinek was staged by Sanford Sylvan for the Boston Conservatory's Opera Department in 2007. He is the co-artistic director of Guerilla Opera since 2007.