It’s a good time for unannounced new songs from hip-hop luminaries! Following Kanye West’s unexpected release of “Power” last week (plus another Rick Ross–featuring snippet, “Monster,” this afternoon), a Swizz Beats–produced Jay-Z song, “Ultra,” has popped up. No, there isn’t a secret Jay album on the horizon: It’s actually a reference track for Last Train to Paris, Diddy’s upcoming, vocal-technique-groundbreaking album. Technically, Diddy should be embarrassed that the version of the song he has not yet rerecorded has leaked, but the guy’s never been shy about his use of ghostwriters (and we quote: “Don’t worry if I write rhymes, I write checks”), and getting Jay-Z to toss him a verse actually earns Paris cred points more than anything. (Also, we are now, at the very least, excited to find out what other talented rappers Diddy got to write verses for him on this thing.) And besides, it’s always a good time when these things leak, for the strange allure of hearing one guy rapping as if he were another guy; on “Ultra,” Jay’s Diddy impersonation mostly consists of shouting out Ciroc vodka and interesting haircuts, and being slimily braggy about his wealth. It's worth the price of admission alone to hear him go “no limit keep spending got no regard/me and Hov two guys playing bumper cars.” Is that speaking in the fourth person?