Jay-Z's "Threat" is the song that really seemed to catapult 9th Wonder's career. I first heard of 9th when he remixed Nas' album calling it God's Stepson. Not long after I became a fan of Little Brother (starting with The Listening) and it seemed like a pretty major thing for him to have a song on Jay's album.
"Threat" isn't my favorite track on the Black Album. "Allure" probably is, but there really isn't a bad song on it at all. It's an undeniable classic (as are Reasonable Doubt and The Blueprint). He rips it start to finish, and its replay value is huge to me. I've probably heard it well over a hundred times now. Plus all of the remixes that were done after the A Capellas were released, which seemed infinite there for a while. 'Threat' stuck out to me though as especially clever.
It's great because it's making fun of rappers who make threats on wax all day by doing an impression of them, but with a real MC's skill to elevate it above their level. Jay-Z's lyrics, and the way he structures his bars make this song great. And, the added joke on rappers without any names needing to be named makes it classic. Jay has always excelled at doing that though - see the third verse on "Trouble" from Kingdom Come, or his verse over "Scenario Remix/Pump It Up" from S. Carter Collection for more proof. The comedy of this song though is what sets it apart.
It's over the top and funny with Cedric The Entertainer's vocals, and 9th Wonder really did a brilliant job with the sample. There is a reason why this song put him into the much sought after class of producer he is today. It's pretty damn perfect. I'm not sure how the whole song came about. If Jay had the idea for the sample, or he just picked it from 9th. Did they cover this song in the documentary? Haven't seen it in a while. Anyway, instrumental is below.