My background is in performance - I have a bachelor's and a master's (3.99 GPA for what it's worth). I was told this could be a serious detriment to me and that I would need to highlight my scholarly activity. Without a master's in musicology specifically, it's important to show otherwise that you can write well and conduct research. I have one journal publication and 3 conference reports under my belt, so I pushed these facts really hard in my applications. I used my published article for my writing sample, and have been told I was brought in for an interview in large part based on that writing sample. That is by far the most important element of a musicology application, I believe. I've been teaching for 2 years (music appreciation) at a large University, so I'm sure this helped me, as well. Still, I only was accepted to 2 universities. However, one of them was my top choice, so I am ecstatic. The reason it was my top choice was because of fit, and I have been in contact with my POI for 2 years now, so I recommend figuring out who you want to study with and get in touch with them ASAP. Since there are many good candidates and most of these programs bring in only 2 people a year, it really comes down to fit.