Watch the Intervallic Jumps online guitar lesson by Jennifer Batten from Rock Sauce For Lead Guitar
An interval is the distance between two notes. In typical playing, the intervals are pretty small i.e. seconds or thirds. Intervallic playing makes use of bigger distances like fourths and fifths more commonly. It gives both your left and right hands a workout if you're not used to picking such big jumps. The king of intervallic guitar playing would have to be Joe Diorio. He wrote a book called "Intervallic Designs For Jazz Guitar" but it certainly is not limited to any particular genre. When I first heard Joe play, I was intrigued by how fresh his lines sounded. At one point I memorized his book. I use his concepts a lot and have also combined intervallic phrasing with two hand tapping.