Hexatonic scale
The scales listed here are mostly artificial constructions and do not form the basis of any lyrical tunes which is why none have been proposed below. However Irish and Scottish and many other folk traditions use six note scales. They can be easily described by the addition of two triads a tone apart. ie Am and G as in tunes like Shady Grove. This scale is a very large part of the aural history of music. I encourage anyone who is actually interested in six note scales to look at a book of folk tunes and observe how many omit either the fourth or the sixth from the seven note diatonic scale and are therefore hexatonic in character.
In music and music theory, a hexatonic scale is a scale with six pitches or notes per octave. Famous examples include the whole tone scale, C D E F♯ G♯ A♯ C; the augmented scale, C D♯ E G A♭ B C; the Prometheus scale, C D E F♯ A B♭ C; and what some jazz theorists call the "blues scale", C E♭ F G♭ G B♭ C. A hexatonic scale can also be formed by stacking perfect fifths, this results in a diatonic scale with one note removed (for example, A C D E F G).