Bienen does give merit scholarships: “Each year, the Bienen School of Music will also award selective merit-based scholarships to those whose musical auditions demonstrate remarkable excellence.”
You need to formally declare NU as the first choice to access the NMF scholarship: https://undergradaid.northwestern.edu/types-of-aid/scholarships-grants/northwestern-scholarships.html#merit
I would contact NU directly to ask the ED question.