Norman Whitfield , who died on Tuesday aged 67 , was a songwriter and producer and one of the principal architects of the Motown sound ; he was responsible for many of the label 's greatest hits , including such classics as Money ( That 's What I Want ) and I Heard it Through the Grapevine , a chart-topper on both sides of the Atlantic in 1968 that became the biggest-selling record in the label 's history .