September 15, 1956 - Elvis Presley started a five-week run at No.1 on the US charts with 'Don't Be Cruel'. The track went on to become Presley's biggest selling single, with sales over six million by 1961. This “double-sided hit” which had 'Hound Dog' on the B side, became the most successful on Billboard’s Hot 100 chart. One side reached No.1 on the chart, the other No.2. The two titles spent a combined 55 weeks in the Top 100 in 1956-1957