Practical definition for piano: fifth means either skip four keys or skip five keys. Consider what you get when you play two white keys by skipping three, either playing one then the other going either way, or both together. Read further at your own risk!
- Generally 5ths come int two sizes: large and smaller.
- 5ths use 5 letters total
- 5ths played on white keys are usually perfect 5ths. B F is the single exception. It is a diminished 5th.
- Perfect 5ths can also be two black keys. In fact, all perfect 5ths are two white keys or two black keys, with two exceptions.
- The two exceptions are the Odd Balls: B F# and Bb F.
- You can combine 5ths in this way: two perfect 5ths make a maj7 chord. Two diminished 5ths make a dim7 chord. A perfect 5th + a diminished 5th combine to make a 7 chord