can ya help?

I'm in a class this semester called 'Congregational Song'. Our assignment for next week (due Monday) is to find 3 biblical examples of Congregational Song. We have to state where it's found, who/what group of people are singing, why/what prompted it, and the result (if there is one).

I have searched the obvious words like praise, song, singing, worship... and i have found some stuff that i think will work. But I would like to have more passages/examples to choose from if any of you people out there reading this can think of some examples and care to share.

umm... i'm a visual learner - i can't do the whole 'let me tell you something and you write it down as fast as you can' thing.... and i kind of dozed off during his description/example. So from what i can recall his definition of Congregational Song was something like this - anything sung by a group of people who are together to worship God, not performing for other people, but as a vehicle for their worship.

I don't know what constitutes a 'group'. And i don't even know if constitutes is the right word, but it sounds really smart so i'm using it. I mean, Paul and Silas sang hymns at midnight when they were in prison - so does 2 people equal a group?

Anywho, if you have any examples that you can think of or come across within the next 5 days i would really appreciate them! Have a great week!