Chakra Crystal Singing Bowls 7th chords (4 note harmony): 7th chord vocal harmonies can create tension and anticipation, but can also be very pleasing to the ear if used correctly.
G7: G B D F
D7: D F# A C
A7: A C# E G
E7: E G# B D

4 - Tone Harmony (chords):
C Major seventh chords C (root), E (major third), G (perfect fifth), B (major seventh)
D minor seventh D (root), F (minor third), A (perfect fifth), C (minor seventh)
E Minor seventh E (root note), G (minor third), B (perfect fifth), D (minor seventh)
F Major seventh F (root), A (major third), C (perfect fifth), E (major seventh)
G Genitive seventh chord G (root), B (major third), D (perfect fifth), F (minor seventh)
A Minor seventh A (root), C (minor third), E (perfect fifth), G (minor seventh)
B Half diminished seventh B (root note), D (minor third), F (diminished fifth), A (minor seventh)

5 - Tone Harmony (scales):
C Major pentatonic C, D, E, G, A
D Minor pentatonic D, F, G, A, C
E Minor pentatonic E, G, A, B, D
F Major pentatonic F, G, A, C, D
G Major pentatonic G, A, B, D, E
A Minor pentatonic A, C, D, E, G

6 - Tone Harmony (Scales):
C Major scale C, D, E, F, G, A, B
D Dorian mode D, E, F, G, A, B, C
E Phrygian mode E, F, G, A, B, C, D
F Lydian mode F, G, A, B, C, D, E
G Micridian mode G, A, B, C, D, E, F
A Aeolian (natural minor): A, B, C, D, E, F, G

7 - tone harmony (scales)
C Major scale C D E F G A B C
D Dorian mode D E F G A B C D
E Phrygian Scale E F G A B C D E
F Lydian mode F G A B C D E F
G Micridian modulation G A B C D E F G
A minor (Aeolian) scale A B C D E F G A

B Locrian modulation B C D E F G A B
Self-exploration is encouraged when playing the Chakra Crystal Singing Bowls, trying to create your own unique sound and healing vibe. However, it is recommended to start and end on the same notes. If you are a beginner it is best to mimic and learn specific scales played by a sound healer to start with. These are some of the most common harmonies, but there are many other possibilities after experimenting with combinations.