4/6. As the pop single continues to hold its own in the digital era,
Tony Visconti singles out six 45rpm hits for their lasting significance. The survey continues with Blondie's widely adored transatlantic number one smash Heart of Glass. Their fifth UK chart hit, it marked a radical shift from their signature "new wave" sound, thanks to producer Mike Chapman 's controversial disco imprint, and finally broke the band in their native America. Characterised by Deborah Harry 's sensual delivery, Heart of Glass sold a million copies in the UK alone on the strength of 12 weeks in the charts in early 1979.