The eerie human-esque sounds overlaid with Dies Irae creates a “Native American/ghosts" connection.
The only visual connection to this are the ghosts we see are of the wealthy inhabitants of the hotel, and the decorations from the culture of Native Americans.
In this image · No.2
Dies Irae, the Day of Wrath, describes the day of judgement. Its use connects the soundtrack with fatalism and American History.