In this lesson you will be asked to play a perfect 4th on your instrument by name.
As we learned in the previous lesson, counting up four degrees from almost any note in the scale yields a perfect 4th.
This is true in any key, not just the key of C.
The one exception is when starting from the 4th note in the scale, in this case F.
This yields a so called Augmented 4th because it is 6 half steps instead of 5.
Therefore, if we want to play a Perfect 4th starting on F, we must flatten the upper note to remedy this problem.
Generally, if we just follow the rule Whole, Whole, Half, we will get the desired result.
For example, if we wanted to play a Perfect Fourth starting on Eb we would go Whole, Whole, Half and arrive at Bb.
An interesting fact about Perfect 4ths is that both notes will almost always have the same accidental.
That is, if one note is a sharp, the other note will almost always be a sharp as well.
The only exception is starting on F or F#, for the reasons mentioned before.
Please press the Exercise button below.