Ludacris featuring Nicki Minaj
"My Chick Bad"
(Venus & Serena mention at 0:45)
(Serena mention at 3:05)
(a very special dedication at 4:10)
"Venus (I'm Ready)"
(the entire song is a Venus shout-out!)
Also All I Need by Chris Brown feat. Wale (Serena mention at 3:22) and So Many Girls by DJ Drama feat. Wale, Tyga and Roscoe Dash (Venus and Serena mention at 1:20). Warning: explicit lyrics.
And then, of course, there's the queen of the WTA herself taking the microphone... check it out: