I think these are all Korean- American rappers. The first video is by a rapper named Lyricks called letters to Rook, who was another Korean American rapper but recently passed away. The second video is by Lyricks and another named JL called seven rings. The third song is by Danny Chung aka Decipher called Norma Jeane. I found all these guys on YouTube and if you haven't go check them out (well, if you want to.) They all have really good music (imo, lol) and so do other artists they work with.