For their fourth album, 1981's Ghost in the Machine, the Police had streamlined their sound to focus more on their pop side and less on their trademark reggae-rock. Their jazz influence had become more prominent, as evidenced by the appearance of saxophones on several tracks. The production has more of a contemporary '80s sound to it (courtesy of Hugh Padgham, who took over for Nigel Gray), and Sting proved once and for all to be a master of the pop songwriting format. The album spawned several hits, such as the energetic "Spirits in the Material World" (notice how the central rhythms are played by synthesizer instead of guitar to mask the reggae connection) and a tribute to those living amid the turmoil and violence in Northern Ireland circa the early '80s, "Invisible Sun." But the best and most renowned of the bunch is undoubtedly the blissful "Every Little Thing She Does Is Magic," which topped the U.K. singles chart and nearly did the same in the U.S. (number three). Unlike the other Police releases, not all of the tracks are stellar ("Hungry for You," "Omegaman"), but the vicious jazz-rocker "Demolition Man," the barely containable "Rehumanize Yourself," and a pair of album-closing ballads ("Secret Journey," "Darkness") proved otherwise. While it was not a pop masterpiece, Ghost in the Machine did serve as an important stepping stone between their more direct early work and their more ambitious latter direction, resulting in the trio's exceptional blockbuster final album, 1983's Synchronicity.