Subscribe: www.youtube.com/subscription_center?add_user=SimplyRedVideo "If You Don't Know Me by Now" is a song written by Kenny Gamble and Leon Huff and recorded by the Philadelphia soul musical group Harold Melvin & the Blue Notes, which became their first hit after being released as a single in 1972, topping the R&B chart and peaking at number three on the Pop chart. It was covered by Simply Red in 1988, and became a wordwide hit reaching number one on the U.S. Hot 100 on July 15, 1989 and peaking at number two in the UK Singles Chart. It also topped the Canadian Singles Chart.