That's not likely to draw an arrest, I don't think.
But I wouldn't want to put anything past the Capitol Po-Po.
Maybe Singing, Praying and Dancing, all at the same time. I just saw this article -- dancing is a crime in Japan.
http://www.tofugu.com/2012/05/16/is-dancing-illegal-in-japan/
The point of the article is that Japanese police aren't saying why they're choosing to make arrests of people dancing in public. They just are, they continue to choose to do so, and people are supposed to be on guard. "Choose when and where you dance wisely," the message seems to be.
That's just so f'd up on soooo many levels.
...But getting back to your point, yes, maybe it would be a good idea to push the envelope a little.
Different people may naturally have more or less interest in singing (I always have more fun moving to a rhythm and beatz, myself and I'm a t e r r i b l e singer) and others might be more drawn to public prayer groups.
Make protest a multiple choice option, not one-size-fits-all.
Edit to add link:
For instance, at this nuclear weapons base in Germany, there were many separate, distinct interest-groups: Poetry, Inter-Religious, Rhythm, Women's, a 'Happening' group... it was "complicated" but it worked.
http://www.counterpunch.org/2013/08/15/german-bomber-base-shut-down-by-ambitious-rhythm-beats-bombs-blockaders/