Dr. Dre 's signature `` west coast whistle '' riffs are present in the song Some L.A. Niggaz .
During this period , Dre 's signature `` west coast whistle '' riffs are still present albeit in a lower pitch , as in `` Light Speed '' , `` Housewife '' , `` Some L.A. Niggaz '' and Eminem 's `` Guilty Conscience '' hook .
Dr. Dre