They walked into a recording studio in the early 1990s and stacked harmonies so precise that other vocal groups started taking notes after hearing the playback. Boyz II Men were four guys from Philadelphia who met at the High School for Creative and Performing Arts and decided that what R&B needed was a return to group harmony -- not a quartet with one lead and three background singers, but a group where every member could carry the melody on his own. Nathan Morris, Wanya Morris, Shawn Stockman, and Michael McCary signed to Motown in 1990 and brought a doo-wop sensibility into the new jack swing era without ever sounding retro.
The cost of that precision was the pressure of their own success. Their debut album Cooleyhighharmony in 1991 went nine times platinum on the strength of MotownPhilly and It's So Hard to Say Goodbye to Yesterday. Then End of the Road arrived in 1992 and spent thirteen weeks at number one on the Billboard Hot 100, a record that stood for two decades. The bar was set so high that every subsequent release had to clear it, and the group spent the rest of the decade trying to match a standard they had set for themselves. I'll Make Love to You in 1994 also reached number one and stayed there for fourteen weeks.
End of the Road is a masterclass in what four voices can do when trust between them is complete. Wanya Morris's lead vocal comes from a place of genuine grief, the harmonies rise behind him like a congregation responding to testimony, and the bridge where the group locks into a single sound seems to come from one throat rather than four. The song won three Grammys and became the blueprint for how to make a breakup song feel communal rather than lonely. The group released II in 1994, which sold twelve million copies.

They kept releasing hits through the 1990s. The lineup changed when McCary left due to a health condition, but Boyz II Men proved that vocal groups did not need choreography or visual gimmicks to succeed at the highest level. Four voices that trusted each other completely were enough to carry an entire era of R&B.