A recently leaked bootleg tape called “New Jacks” by Emcee Double M (Eminem) and DJ Butter Fingers contains some very gritty two track recordings of 16 year old Eminem rapping over popular rap beats of the time. (Eat It and Teachin’ You A Lesson)
Dj Amsterdam took those two track recordings, and re-sampled the beats using the highest quality files available. Then he cleaned up the vocal track, and layered it on top of the newly made beat.
Here is 1988 Eminem performing “Teachin’ You A Lesson” over N.W.A’s “Dopeman”