Motown songwriter and producer Norman Whitfield, whose credits include hits I Heard It Through The Grapevine and War, has died in Los Angeles. Whitfield, 67, worked at the legendary label in the '60s and '70s, adding a rock edge to soul music. Many of his hits were co-written with Barrett Strong, with whom he was inducted into the Rock and Roll Hall of Fame in 2002.  The pair won a Grammy in 1972 for Papa Was A Rolling Stone by The Temptations.  The Temptations' chart hits were all Whitfield's work, and he was their chief producer from 1966-74.  The songwriter also co-wrote and produced songs for Gladys Knights and The Pips.  He scooped another Grammy award in 1976 for the theme tune to Car Wash, which went on to become a chart hit for Rose Royce.    Whitfield's only track to reach number one was 1970's politically-charged War performed by Edwin Starr, which he also produced.                           " BBC Marvin Gaye's classic I Heard It Through The Grapevine, produced by Whitfield, was recently ranked at 65 in Billboard's 100 most successful tracks of the last 50 years. Singer Smokey Robinson, one of Motown's best-known artists, hailed Whitfield as "one of the most prolific songwriters and record producers of our time". "He will live forever through his great music," he added. BBC