Most nationalities singing a national/regional anthem simultaneously

Most nationalities singing a national/regional anthem simultaneously
Who
Watani Al Emarat Foundation
What
120 total number
Where
United Arab Emirates (dubai, --None--, United Arab Emirates)
When

The Most Nationalities Singing a National/Regional Anthem simultaneously is 120, and was achieved by the Watani Al Emarat Foundation (UAE), in Dubai, UAE, on 27 November 2019.