During the 1960s, the Motown record label developed a popular and influential own sound, described as having "1) simply structured songs with sophisticated melodies and chord changes, 2) a relentless four-beat drum pattern, 3) a gospel use of background voices, vaguely derived from the style of the Impressions, 4) a regular and sophisticated use of both horns and strings, 5) lead singers who were half way between pop and gospel music, 6) a group of accompanying musicians who were among the most dextrous, knowledgeable, and brilliant in all of popular music (Motown bassists have long been the envy of white rock bassists) and 7) a trebly style of mixing that relied heavily on electronic limiting and equalizing (boosting the high range frequencies) to give the overall product a distinctive sound, particularly effective for broadcast over AM radio." Motown had many hits with early disco elements by acts like the Supremes (for instance "You Keep Me Hangin' On" in 1966), Stevie Wonder (for instance "Superstition" in 1972), The Jackson 5 and Eddie Kendricks ("Keep on Truckin'" in 1973).