OpenStax
Open Stax: Catherine Schmidt Jones: Scales That Aren't Major or Minor
As the title suggests, this site defines and gives examples of various other types of scales including chromatic, whole tone, blues scales and more.
Open Curriculum
Open Curriculum: Scales That Are Not Major or Minor
To explain the various musical scales that cannot be classified as major or minor such as chromatic, whole-tone, pentatonic, blues, and scales from non-Western music
Rock and Roll Hall of Fame
Rock & Roll Hall of Fame: Sti Lesson 44: Compositional Techniques
Young music students rarely see or, better still, hear a connection between the different types of scales, modes, intervals and other compositional techniques such as meter, tonality, and form used in both traditional 'Art' music and...