Mama Said Knock You Out

LL Cool J appears shirtless on the cover of his fourth album, his chest and arms lit in warm, gritty tones, a heavy chain around his neck and his fists raised in front of him like a boxer waiting for the bell.

By 1990 critics had written LL off as a pop rapper past his peak. With Marley Marl producing, he answered with a hard comeback record, and its title track, inspired by his grandmother's advice to knock his doubters out, opened with "Don't call it a comeback, I been here for years." The song won a Grammy, and the album became one of the biggest of his career.

The boxing pose turned the title into a picture. The cover presented LL as a fighter returning to the ring, and the image of the bare-chested rapper with his fists up became one of the most recognisable in early-1990s rap.