"If You Don't Know Me By Now" is an all-time landmark of Philly soul, and made Harold Melvin & the Blue Notes one of the style's biggest groups with its breakout success in 1972. The song was originally written by Philadelphia International label honchos Kenny Gamble and Leon Huff for Marvin Junior of the Dells, whom they were aggressively trying to sign. When the deal fell through, the Blue Notes were the beneficiaries of much of that material, since they'd recently discovered a new singer with a similar baritone range: a dynamic young drummer turned frontman named Teddy Pendergrass. Pendergrass made himself a star on "If You Don't Know Me By Now," his second single with the group; right from the first line he intones, the passion, vulnerability, and off-the-beat phrasing mark him as R&B's next great singer. The song's loose, spacious arrangement and particularly slow tempo give Pendergrass plenty of time to stretch out his lines, and he begs his longtime lover for understanding as if the fate of the world depended on it. It's a distinctly adult love song, since it's clear that the lovers have been together for quite some time ("ten long years," as Pendergrass ad-libs in the outro), which makes their communication problems all the more frustrating. The song could capture the moment of a relationship being saved, or the beginning of a breakup or divorce, and Pendergrass conveys the crisis with tremendous intensity, supported by a slick, near-epic production and smooth backing vocals from the Blue Notes that contrast nicely with his rough pleading. "If You Don't Know Me By Now" hit number one on the R&B charts and reached number three pop, making it far and away their biggest success on the latter; 17 years later, the song topped the pop charts thanks to a cover by Simply Red. Yet even if Mick Hucknall is a highly credible blue-eyed soul singer, his rendition can't quite match the jaw-dropping power of Pendergrass and the magnificent production of Gamble & Huff.