Didi Kirsten Tatlow, New Tone in Chinese Media; Digital paper covers corruption and scandals now even in English, under party control. New York Tumes, Apr 6, 2015.
(b) "On Wednesday [Apr 6] it is set to publicly kick off an English-language version called Sixth Tone 第六声 in hopes of making its recipe for success in China work abroad."
(c) "Mr Wei [Xing, its editor and the former deputy editor in chief of The Paper,] hopes the website's name reflects how they want to meet it: Mandarin Chinese has five tones, including a lesser-known fifth, 'no-tone' tone. 'We want to be the sixth one. We want to be fresh and different,' he said."
(i) The translation by cn.nytimes.com: "曾担任澎湃副主编、现任第六声编辑的魏星."
(ii)
(A) The "sixth tone" is also a music interval, whose duration I do not know. https://en.wikipedia.org/wiki/Sixth_tone
(B) In addition, spoken Cantonese is said to have "six tones."