Every scale is related to the Major scale because all scales are derived from the Major scale through various alterations and modifications. The Major scale serves as the foundation for understanding and constructing other scales in music theory. The relationship between the Major scale and other scales can be seen through the concept of intervals, which are the distances between the notes in a scale.

Examples of how scales are related to the Major scale:

Natural Minor scale: The natural minor scale is derived from the Major scale by starting on the sixth degree of the Major scale. For example, the C Major scale is C-D-E-F-G-A-B, and the A natural minor scale is A-B-C-D-E-F-G. The intervals of the natural minor scale can be expressed as a sequence of whole steps and half steps, similar to the Major scale.
Melodic minor scale: The melodic minor scale is another variation of the minor scale that is derived from the Major scale. It is formed by raising the sixth and seventh degrees of the natural minor scale when ascending, while using the natural minor scale when descending. For example, the A melodic minor scale is A-B-C-D-E-F#-G#, which is different from the A natural minor scale (A-B-C-D-E-F-G).
Blues scale: The blues scale is a commonly used scale in jazz and blues music that is based on the minor pentatonic scale. The minor pentatonic scale is derived from the natural minor scale by removing the second and sixth degrees, creating a scale with five notes. Adding the tritone interval between the fourth and fifth degrees of the minor pentatonic scale results in the blues scale, which has a distinctive bluesy sound.
Dorian mode: The Dorian mode is a type of scale that is derived from the Major scale by starting on the second degree of the Major scale. For example, the D Dorian mode is D-E-F-G-A-B-C, which is the same as the C Major scale starting from D. The Dorian mode has a unique character and is commonly used in jazz and fusion music.

In summary, every scale is related to the Major scale because they share a common origin and can be understood in terms of modifications and relationships to the Major scale. By recognizing these connections, musicians can better understand the structure of scales and how they can be used in creating melodies, harmonies, and improvisations in music.