The Isley Brothers' 12th studio album, “The Heat Is On,” became the long-standing group's first number one album on September 13, 1975. The album, which spent 40 weeks on the Billboard Pop Albums chart, sold 500,000 copies in its first month of release. “The Heat Is On,” contained the singles “Fight The Power (Part 1 & 2)" and “For The Love Of You (Part 1 &2).” The album's popularity has sustained throughout the years; it was certified double platinum in 1999.