By definition, a pentatonic scale contains five pitches per octave. Ir can be formed in any major or minor key. To derive the major pentatonic scale from the major scale, simply remove the 4th and 7th degrees, which leaves you with five notes per octave.
Therefore, its scale degrees are 1, 2, 3, and 5. For example, to derive the C Major pentatonic scale from the C Major scale c-d-e-f-g-a-b-c, simply remove the 4th (f) note and 7th (b) note from it. The C Major pentatonic scale then consists of the notes c-d-e-g-a.
The scale has a very distinct, pleasant sound that works great layered over many chords and other scales. It contains the most commonly used pitches in many popular songs. Its lack of half-steps contributes to its distinct sound, as compared to a major or minor scale.