Watch the 5ths online guitar lesson by Charles Chapman from Interval Insights
The 5th is a very common interval and one of the most recognizable. Both the root and 5th of the chord are what we are used to hearing in the bass motion of any standard song, and they form the root-5 "power chord" so pervasive in rock music. The 5 (V) to 1 (I) change is the most common way to end a section or final cadence of a tune. In classical literature this V to I motion is referred to as the Authentic Cadence.
A note on the exercises: When the same finger is notated for two different notes on the same fret, the "rolling finger technique" is often useful. With the side of your finger, roll either backward or forward to get the new note. This tends to have more accuracy and a smoother sound than the straight barre.
1- 5ths Played Single
2- Played Single Ascending 5ths in 3rds
3- Played Single Descending 5ths in 3rds
4- 5ths Played Simultaneous
5- 5ths Played Simultaneous in 3rds