What's the group noun for angels?

It's sometimes quite weird working in publishing. Just as the temperatures soar, and everyone is walking round in shorts eating ice creams, what are we doing? Writing stuff for Christmas!

Been working with GBCs outstanding childrens' editor Alison Mitchell on a new tract for Christmas for children. I stopped short at the sentence that said:

"A bunch of angels showed up and started singing praises to God"

What exactly is the group noun for angels? Alison originally had "troop" but thought it sounded a bit too militaristic. Not a bad idea, as the host of heaven sometimes acts as an army. But a brief brainstorm in the office came up with some other suggestions:

• A Flock of angels: quite fun if you imagine angels to be of the wing-ed variety. But Bible scholars who routinely score 7 out of 7 on our weekly Blog quiz will instantly wag their fingers - only the cherubim and seraphim are described as winged, most other angels are more like shiny people.
• A Host of angels: that's the biblical term, but it is a bit of a "Bible vocabulary word" that children wouldn't get that easily
• A Pinhead of angels: suggested by Carl Laferton. not a reference to my legendary small brain, but to the arguments about how many you could fit on one...
• A flashmob of angels: loved this one as it is trendily modern and also describes the way a group of angels show up and... well... flash

Any suggestions to help us out are warmly welcome...