I'm not a singer and am unfamiliar with the descriptive characters of choir music. What I'm trying to figure out is the linked tone between the psalms of Byzantine chants. There seems to be a deep, dark, serious and/or moody tone to them which is not necessarily shared with other Byzantine chants or other similar chants of medieval religious origin which I've heard. The later tend to have a sort of energetic, airy or sad (among other tones that I lack great descriptors). I'm interested in learning more about the psalm characteristics so I can be more informed about this music which I thoroughly enjoy. Thanks in advance!

Examples:
Joseph Yazbeck - Psalm 33

Joseph Yazbeck - Psalm 144