I hold a Masters in Music Education, but am interested in broadening my marketability. Can you advise a direction for someone like me?
Should I look at a second Masters or a PhD?
- answers

Humm... That is a very tough question. Advising you on what your next step is going to be is not really possible without knowing what other skills and education you possess.
What I would suggest you do is take a long look at your interests. Evaluate what you enjoy doing, what you are good at, and what direction would be most advantageous to your over all life goals. If you are planning on staying within you music education field, having a master degree will just about do it, unless you are looking to get a teaching position within a university or college setting - in which case you will need a PhD. But I warn you, if you are not planning on this, make sure you do not educate yourself out of useful employment, which is common with PhDs.
As for a second Master's degree, that will depend on what you are planning on. If you are considering leaving the field of music education all together, than this might be an option to consider; however, if you are not, then I don't really see how it could help - other than put you in to debt/more debt.
Overall, increasing you marketability will just depend on what you want to do. Take a look at the current trends in the fields you are interested, and start positioning yourself for meeting their requirements - whether through online degrees, , certifications.
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