Rock music isn't as clear-cut as the blues. The blues is based on repeating chords, so applying chords and solos to the blues is simple because of its repeating nature. Rock has no common traits—every artist and group does something a little different. While it's true that early rock stemmed from blues, and shares some common traits with that genre, the evolution of rock music has taken no specific direction. Almost anything goes. You can turn any of the chords and keys you learned in earlier chapters into riffs for songs and solo ideas. Rock music, especially modern rock music, manifests itself in many different keys. So, unlike the last chapter on blues, this chapter shows examples spread across a spectrum of keys.