Some background. I love biology and want to go to school to become a biomedical engineer but that would take a lot of schooling and money, but I think it would be worth the rewards. The thing is, a big part of my life is also music (I play the flute) and I don’t want to give it up, which I will have to if I pursue a biomedical degree. Math is also my strongest subject I guess you could say. I don’t love it as much as bio, but it comes easily to me and if I got a degree in mathmatics I could be out of school sooner plus double major in music. Math would also be a lot less stressful career wise.
Pros and cons of each? Biomedical engineering only, or double major (or major/minor) in mathmatics and music? I’m torn 
You can play music without majoring in music - you don’t have to give up playing the flute just because you don’t major in music. It can even still be a big part of your life; you can play in chamber ensembles, the student orchestra, and/or marching band. The question is, do you want the intense professional study of music that comes with majoring in music as a college student?
I see a couple other options here, too:
-BME majors do typically take longer than 4 years - 4-5, typically, and sometimes even 6. It depends on where you go and how good you are at it. Those majors are demanding, but engineering majors still do have time to pursue a few interests outside of academics if they manage their time well. So you could do that.
-You could major in math and minor in biology. There are tons of biomedical careers that could use someone with strong math/statistics skills and knowledge of biology. In this scenario you keep music as a hobby - take classes in it, play in your school’s orchestra or flute ensemble or both - but focus your academic efforts on math and bio.
-Major in bio and minor in math, or double-major. Same deal as above, just switched.