The New Zealand music industry is celebrating its ruby anniversary of the official NZ Top 40 music charts. Some of Kiwi music royalty were among those honoured at an event at Auckland's Vector Arena last night. Recorded Music NZ, who runs the official top 40 charts, is also releasing a limited edition 7inch pressed on ruby red vinyl with proceeds going to the music foundation. So who were the big names last night and what makes a top hit? Recorded Music CEO Damian Vaughan joins Mike Hosking to discuss.