What does “BO!! SELECTA!!” mean? I’ve heard this in some of Craig David’s and also MJ Cole’s tracks… And Ali G sometimes says it too…
BO = Atttention i.e. Hey!!
Selecta = the DJ
So basically “Hey DJ”
“BO!” is also just a general cooler-sounding “WOO!” noise. It’s a random thing to shout. Ali G (the guy driving the car in Madonna’s Music video) says it a lot for comic effect and so it’s a bit of a passe thing to say now. At least, it is for those in the know 
Fran
Cool, thanks for that guys. It’s not very well known at all in Australia, so I guess I’ll just keep sayin it 