According to no less an authority than the RIAA, Boyz II Men are the most commercially successful R&B group of all time. They've sold ludicrous numbers of records and been involved in three of the longest-running number one pop singles in history, and they've done it as a unit of equals.
source: www.allmusic.com
In fact, their four-part harmonies blend so smoothly that most of the general public would be hard-pressed to name any of the group's individual members. And that's no reflection on their skill as singers; Boyz II Men were among the first male urban soul artists to adopt the sort of hyper-technical melodic embellishments that were popularized by virtuosic divas like Whitney Houston and Mariah Carey.
Their early music was indebted to new jack swing, but the group quickly found their forté in lush, soulful ballads, where their harmonies could be showcased to greatest effect. Boyz II Men may never duplicate their incredible run of success during the first half of the '90s, but that's a near-impossible task for anyone, even with the broad-based appeal of their clean-cut romantic image.