In regard to RZA's contributions to the album, Method Man explained:
"RZA was the first name I said when I spoke to Jay-Z, when he signed off on the album budget. I’m happy with the outcome, but I think RZA could have had a little bit more input, but he was busy at the time."
"This is just more RZA on production, shit like that. But some of the shit I couldn't do, because some of these producers were screaming out these niggas want a $100,000 for a track. Fuck that! Kiss my ass. I'm not paying nobody a $100,000 for shit, unless I can live in that mothafucka."
Method Man explained the album's title:
"The national weed smoking day is 4/20, so I named my album 4/21 the day after. Because after that day, you have this moment of clarity when you’re not high and you see things clearly."