Fats Domino was a pianist, singer, and songwriter who made a name as one of the biggest stars of the early rock-and-roll era. His file consists of a 1965 inquiry into one of his Cadillacs, apparently spotted during an FBI stakeout of a Philadelphia hotel that Martin Luther King was believed to be staying at.
The document in Domino's file is labeled "SUBJECT: MARTIN LUTHER KING, JR." and refers to an earlier airtel from the FBI's Philadelphia office. That earlier message is included below for reference, and describes an "extremely discreet spot check at the Franklin Motor Inn," during which Domino's car was spotted and—it seems—mistakenly connected with King. The original document can be found in context in MLK's complete FBI file, which runs to over 16,600 pages. The Philadelphia airtel begins on page 49 of file 32.
New York Times obit: Fats Domino, Early Rock ’n’ Roller With a Boogie-Woogie Piano, Is Dead at 89