evidence: Retro pop icon Tom Jones is postponing a U.S. concert tour due to health concerns, the 77-year-old Welshman told fans Saturday via Twitter. Jones, whose career spans six decades, was scheduled to start an ambitious Stateside tour on Sept. 6 in Pennsylvania, but on the advice of his physicians will now embark on those shows in May and June of 2018. The singer did not disclose the medical problem that prompted the change in plans. Tickets for the 2017 shows will be honored for the new dates or can be turned in for refunds. [...] Jones has been struggling emotionally since the 2016 death of his wife Linda, to whom he’d been married for 57 years.