It's also very easy to hear the similarities between Peking and Mandarin... clearly they are related in every aspect except for k > j Whereas for Cantonese, th

It's also very easy to hear the similarities between Peking and Mandarin... clearly they are related in every aspect except for k > j Whereas for Cantonese, there's difference in vowel quality and the final -k of 北. It wouldn't be misinformation if Mandarin indeed used to be pronounced similar to Cantonese... but that's just not true since earlier Mandarin never had -a- for the vowel of 北; it was an innovation in several southern Chinese languages. At best we can say that they used to be pronounced like their Middle Chinese ancestors.