The phrases below have something in common that has nothing to do with their meanings. Can you determine what it is?

HALF SERIOUSLY
GATHERING CLOUDS
WANDERING SOUL
WATERING TROUGH
DATE-NIGHT TOURS
RATE DISCOUNTS
GRAVE MISCONDUCT

Answer:

Each phrase contains the five vowels, once each, in order.

Credit:
NY Times Crossword
September 30, 2007
Kelsey Blakley
FIVE STRING