Sunday night, celebrated coloratura Sumi Jo gave a recital in the Kennedy Center Concert Hall. This concert, which should have been a major musical event, was not publicized well — I did what I could by recommending it the previous Sunday — and therefore sadly undersold. Jo is celebrating her 20th anniversary as an opera singer with a recital tour, apparently self-funded. In true diva style, she wore three different gowns, of increasing levels of…