Need help with identifying a song I heard in school

Well, I hear this song playing in my school, and I can't seem to find out what it is called, so I wonder if any of you can help me? Here is what I know about the song

- a normal beat is in the song completely (pop???)
-There is a constant guitar strum (maybe one or two strings being strung) at the end of its play it strums high a bit then low
- I am pretty sure it is a Black person (or group) singing it
- At the chorus the singing switches from a person singing(rapping?) pretty fast to a group of guys singing sort of high/low at the same time (different voices?)
-I think I hear lyrics in the verse with "try to be optimistic" and in the chorus "Let me take you away" and also in the chorus "I know.." and the beat is almost always constant with the ending guitar strum (only 1 or 2 strings being strung)

That's really all I can think of right now, I'll try to answer any other questions about the song as I can.

bump!

bump!

bump again!

I wish the singer would slow down and be more clear, it is hard to actually hear him clearly x.x

do you have a sample of the song..or a cell phone where you could you record a sample?