It is difficult to choose the right microphone, there are so many of them available. The microphone maker RØDE wants to make its users easier with Soundbooth, an online microphone comparison page.
You can compare several microphones in a blues song by changing the microphones of different tracks, including the drums, vocals, bass and piano. This way you may find that the expensive microphone isn’t needed if you are a good performer anyway.
There is also an iPad version of Soundbooth available.