Punk/post-punk icon John Lydon turns 55 today, and to commemorate, rather than choose between the equally groundbreaking Sex Pistols and Public Image Ltd., here’s something equally important: Lydon’s collaboration with Afrika Bambaataa on Time Zone’s 1984 single ‘World Destruction.’

Although John Lydon has delayed work on a new Public Image Ltd. album over the death of stepdaughter Ari Up, the reunited band will continue performing in 2011, with two new summer festival dates announced this week in the U.K. and Slovakia.

German-born punk pioneer Ari Up — the frontwoman of The Slits who learned guitar from Joe Strummer and was John Lydon’s stepdaughter — died today at age 48 following ‘a serious illness,’ Lydon and her mother, Nora Foster, announced via Public Image Ltd.’s website.

Watch the Waterboys performing their 1988 classic ‘Fisherman’s Blues’ live in Irish radio station RTÉ 2fm’s mobile studio at the Electric Picnic Music & Arts Festival last weekend, where Mike Scott & Co. shared the bill with Roxy Music, Bad Lieutenant and Public Image Ltd., among other bands.

Short-lived British postpunk act The Pop Group — which somehow melded punk, dub, noise and funk — will reunite this September after nearly 30 years apart, with four concerts scheduled in the U.K. and Italy and a new album reportedly in the works.

The reconstituted Public Image Ltd. today canceled the entire mid-August German leg of its ongoing reunion tour over ‘production scheduling problems,’ and said it has no plans to rebook the six scrapped concerts.