Marjukka Riihimäki qualified as a music teacher from the Sibelius Academy in 1972 and teaches at the Sibelius High School in Helsinki. In addition to Grex Musicus she also conducts the Philomela women's choir, the choirs of the Sibelius High School and the women's choir of the Klemetti Institute. Marjukka Riihimäki has been recipient of three major choral awards in Finland.

Marjukka Riihimäki has led her choir to the gold-stamp victory in the Chorus Review of the Tampere Vocal Music Festival on several occations. She has won the Grand Prix with both Grex Musicus and Philomela. Under her, Grex Musicus has been moulded into a chamber choir with a distinctive style and sound that reacts in performance to her radiant conducting mode and elicits praise for its obvious enthusiasm.