Process of how suggestions in issue tracker are reviewed?

I am curious to learn more about how the choices in Musescore's development are made.

Here at www.musecore.org, what is the general review/evaluation process of how suggestions/feature requests, submitted in the "issue tracker", are considered? Is there a "committee" of sorts that regularly collates, reviews and prioritizes all the suggestions to date? (I suspect that in some cases where suggestions are made to improve a specific side-project such as the Piano Roll Editor, the contributing programmer initially decides what to include.). Or does the open-source community-driven nature of Musescore's development, with its multitude of volunteer programmers, make this process of incorporating submitted suggestions more "spontaneous" or "organic", nicer terms than haphazard?

Also, who is/who are the people that ultimately decide whats included in the final product?

Thanks,
Sam