The blues scale is a pretty versatile scale. So it can be used in just about any music, but in blues the "b5" can stand alone in a solo or melody. What I mean is it doesn't have to resolve, like a passing tone would. Example of the b5 as a passing tone (4-b5-5); the b5 resolves to the natural 5th. This example is common in all music, but in blues the b5 is often found unresolved. Other examples which you could mess with and try out are: Say your playing blues in A, you could play a Eb and bend it up to E natural. Common blues technique. Also it's common to play (in A again) D and bend up to Eb. The later is slightly more discordant sounding but alittle more bluesy (downish) in my opinion. The best thing to do is just practice using it over chord progressions, seeing what works and what doesn't.

The blues scale is also common in Rock and Country music. The blues sound can be traced back to the early songs of the slaves who were brought to America. It's even heard in some early classical music.