Impromptu is an unrehearsed speech. Not rehearsing would not allow speakers to gather 100% of their thoughts.
Answer:
Gong Yoo Ma Dong-seok Jung Yu-mi Kim Su-an Kim Eui-sung Choi Woo-shik Ahn So-hee
Explanation:
Here is a website for meaningful poems. I think you can find a good one on here. I couldn't really find a clean meaningful rap song so I tried to find a poem, but I don't know what kind of thing you like so here you go, https://classicalpoets.org/2016/01/07/10-greatest-poems-ever-written/