The genre of rock music is extremely hard to define, especially because it has undergone radical changes every ten years or so. Think of the big change from the '50s sound of Elvis Presley to the '60s sound of Jimi Hendrix. The only thing that you can quantify in rock music is its connection to the blues, because that's where it came from.

Early rock and roll borrowed standard blues chord progressions as the basis for a new style. As the style evolved and grew, there was less reliance on the blues roots of early rock music. Like blues players, many rock guitarists make extensive use of the pentatonic scale for improvisation. As rock has evolved and grown into more progressive and sophisticated sounds, it has also adopted other sounds for improvisation.

Some famous pentatonic-based solos include:

• “Stairway to Heaven,” by Led Zeppelin (A-minor pentatonic)

• “Purple Haze,” by Jimi Hendrix (E-minor pentatonic)

• “Sweet Child of Mine,” by Guns N' Roses (E-minor pentatonic)

• “Freebird,” by Lynyrd Skynyrd (G-minor pentatonic)

• “Crossroads,” by Eric Clapton (A-minor pentatonic)

• “Rivera Paradise,” by Stevie Ray Vaughan (E-minor pentatonic)

Many guitar players use the pentatonic scale as a starting point, adding other notes to the scale to dress it up. While this may be exactly how you want to sound in the end, you have to learn to crawl before you run. Learn the basic pentatonic scale and internalize it before you move on to more advanced topics.