President Obama has nothing but "R-E-S-P-E-C-T" for the women of soul, even if he accidentally misspelled the title of Aretha Franklin's signature anthem.

In an "oops" moment tonight, the president dropped a letter when paying tribute to the one and only Franklin at the White House concert series event, "In Performance at the White House: Women of Soul."

"When Aretha first told us what R-S-P-E-C-T meant to her, she had no idea it would become a rallying cry for African Americans, and women, and then everyone who felt marginalized because of what they looked like or who they loved. They wanted some respect," the president said.

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Making a "quick public service announcement," the president explained that when Franklin first walked into Fame Studio in 1967, most of the other musicians had never heard her sing live before.

"When they did, one of them said, 'The floors rumbled and the walls shook. My brain shook. It was magic,'" Obama said.

"So my advice to everyone tonight is simple: Hang on. The Queen of Soul is in the building. If she blows your mind, it will be OK," he joked. "That's what soul music does. It makes us move and it makes us feel."

Moments later, Franklin rocked the halls of the White House, performing, "I Never Loved a Man."

The president and first lady were also treated to performances by Melissa Ethridge, Ariana Grande, Patti LaBelle, Janelle Monae, Jill Scott and Tessanne Chin.

"That is a line-up! I can't wait!" Obama declared in his introduction.