Answer
$.94$
Work Step by Step
We are interested in the event $E=${regional,poprock,tropical}
The sample size is $N=500$, of which 30 were urban. The frequency of $E$ is $fr(E)=500-30=470$
The relative frequency of $E$ is $P(E)=\frac{fr(E)}{N}=\frac{470}{500}=.94$