Other forms: vibrancies
When something has vibrancy, it possesses deep and rich sounds. The very best singers bring vibrancy to their performances.
Sounds with vibrancy are strong and resonant. You could describe the echoing sound a gong makes as having vibrancy, or the powerful voices of a large choir singing in unison. The noun vibrancy comes from the adjective vibrant, which means "strong and resonating" or "full of enthusiasm and energy." In the 1550's, vibrant meant "agitated," from a Latin root of vibrantem, "swaying to and fro." There's a strong connection between vibrancy and vibrate, or "resonate."