Ja Rule Scoffs at Melle Mel's Claims He Copied 50 Cent, 'I'm the Blueprint'

Ja Rule is literally laughing out loud at Melle Mel's claims he ruined his own "New York" song by copying 50 Cent ... simply because the timelines don't add up!!!

The Furious Five rap legend recently accused Ja of mimicking 50's hood nature on the 2004 track, thus losing the NYC anthem race to Jay-Z and Alicia Keys' hit collab "Empire State of Mind" ... but Ja tells us his record did exactly what it was supposed to do on the charts.

Ja explains his song, which featured Fat Joe and Jadakiss, was a street anthem while Jay and Alicia's classic was created for mainstream platforms like radio -- but he's still proud of its legacy, peaking at No. 27 on the Billboard Hot 100.

As for 50, Ja notes his career as a rapper-singer began first -- he says he laid the blueprint for 50's rap-singing success on songs like "21 Questions," but he adds ... Melle's earned the right to spew whatever opinion he wants.

He also bigged up another hip hop pioneer: KRS-One, whose 1990 "hundred guns, a hundred clips" lyrics fueled Ja's "New York" chorus.