Aretha Franklin performs at the Festival of Families as Pope Francis looks on Sept. 26, 2015, in Philadelphia.
Carl Court/Getty Images

During the final leg of his whirlwind trip to the United States, Pope Francis was treated to a serenade Saturday evening by none other than Aretha Franklin, the Queen of Soul.

Franklin sang "Amazing Grace" backed by a gospel choir at the Festival of Families in Philadelphia before hundreds of thousands of people, one of the largest crowds the pontiff witnessed during his six-day tour of the nation, according to the Daily Mail.

The pope smiled during Franklin's performance, the report notes, but many on social media took his staid composure as a rejection of Franklin's soulful rendition of the Christian hymn that has long been associated with African-American struggles.

https://twitter.com/EClarke1/status/647931920341430272

"But he seemed more impressed by the voice of a young choirboy, who wowed the head of the Catholic Church and an estimated 300,000-strong crowd with perfect falsetto," the Mail writes.

Here are some tweets:

https://twitter.com/barryickes/status/648089596773842944https://twitter.com/BishopHyman/status/647932749651820544https://twitter.com/mallsta/status/647933111100026880

Read more at the Daily Mail.