Douglas McLennan, the proprietor of ArtsJournal, has set up an Arts Blogger Challenge, in conjunction with the next edition of Spring for Music, in May. The initiative has stirred up some opposition, notably from Lisa Hirsch; Doug defends himself from the charge that he is failing to take seriously a discipline that he helped to invent. The deadline for entering is today. (No, I will not be participating.)... Blue Heron, the superb Boston-based Renaissance vocal ensemble, sings at the Cloisters on Sunday.... The St. Louis Symphony's campaign to Save Powell Hall is not quite what it appears to be.... The American Mavericks blitz begins this weekend, with William Basinski and Tristan Perich at the Kitchen, Mary Halvorson and music of the late Arthur Russell at same, Lisa Moore in Queens, and the JACK Quartet. Meanwhile, the Brooklyn Phil is presenting their Brooklyn Village project on Saturday and Sunday.... I caught City Opera's Così fan tutte last night. Christopher Alden's staging starts well, with Sunday-in-the-park, Belle Époque imagery edging into surrealism, but action in the second act slows literally to a crawl. The young British tenor Allan Clayton is the standout in the cast. All told, it's an improvement on the anonymous Traviata last month.... Sarah Baird Knight asks critics, "How do you approach music that draws from multiple traditions, or that falls between genre lines?" An excellent question, worth pondering. Almost all critics are rooted most strongly in one genre or another, and will feel at least a touch unsure when confronted with a hybrid. I wrote about my own insecurities outside the classical zone here. As far as I can judge, there is only one critic actively working who writes about pop and classical music with equal — and great — authority. That is Steve Smith. The New York Times ought to feel lucky to have him.