And why do you need a pentatonic scale lesson? Because pentatonic scales are VERY useful in learning music theory, writing or arranging music, and ESPECIALLY improvising. The word "pentatonic" comes from the Greek "pente" meaning 5 and the Latin "tonicus" meaning tone. So a pentatonic scale is a scale with only 5 tones. there are two standard pentatonic scales: major and minor. They actually are the same scale, just inverted (flipped) differently as I'll explain in a minute.
We'll start with the major pentatonic. As with most scales, we will be working with their scale degrees. A major pentatonic scale consists of 1, 2, 3, 5, and 6. So it is basically a major scale with the 4 and 7 left out.
Ex. C D E F G A B C
C D E G A
Ex. F# G# A# B C# D# E# F#
F# G# A# C# D#
With a minor pentatonic, we use 1, 3, 4, 5, and 7. So it is basically a minor scale with the 2 and 6 left out.
Ex. A B C D E F G A
A C D E G
Ex. D# E# F# G# A# B C# D#
D# F# G# A# C#
Notice how the C major pentatonic and the A minor pentatonic use the same 5 notes and the F# major and the D# minor use the same 5 notes. This brings us and important point:
NOTE: Any key and it's relative will use the same 5 notes for their pentatonic scales.
In almost all music, using pentatonic scales, the chords in the background will be the most helpful way of determining whether it's major or minor.
Most music will be based around the root of the scale. So if you're hearing a pentatonic scale that is in either C major or A minor, listen to see if you're hearing more A's or C's. If you hear more A's, it's probably in A minor. If you hear more C's, it's probably in C. Again, they are the same scales, they are just different in tone or mood.
Minor tones will usually sound more sad and dissonant, and major tones will usually sound more resolved and happy.
Hope this helps! Practice hard and let me know if you have any questions!