Double stops are great addition specially for slap solos. Sometimes they could be used very nicely for regular bass lines as well. I’m not sure why people don’t use them more often.
The easiest one is the perfect fifth aka “power chord” (with index and pinky). If you spend some time, you can also figure out easy ways to incorporate major and minor thirds, perfect fourth and diminished fifth into your playing. The other intervals are easy to play with open strings.
If you check out my Atomic Boogie video (at the bottom of this post) you’ll notice that in the slap part of the solo, I used double stops in 3 or 4 different sections. The solo is ending with the section of 3 note and 4 note chords. That’s just one of the examples of course.
Playing these 2-3-4 note chords on the bass is also very good practice for the intonation.
[url=http://http://www.youtube.com/watch?v=rV0IizvQHW0&feature=related]Atomic Boogie[/url]
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