The formidable young composer/instrumentalist Tyshawn Sorey has a heavy schedule at the end of March. On the 28th, he will have a Portrait Concert at Miller Theatre in NYC, with performances by ICE and the JACK Quartet; on the 29th, he will appear at the Kennedy Center’s Direct Current festival; and on the 31st he will be back in NYC for a Zone Music Workshop with Chris Pitsiokos…. By design, no one is certain quite what will happen at the Yoko Ono evening at Disney Hall, part of the LA Phil’s season-long Fluxus series…. Also in LA, the revitalized Monday Evening Concerts presents Chaya Czernowin’s sensuously engulfing quartet-and-electronics piece HIDDEN with the JACK on March 25…. The Site of an Investigation, a new work for voice and orchestra by Jennifer Walshe, can be seen on YouTube, courtesy of New Music Dublin… The Boston-based vocal ensemble Blue Heron has undertaken a multi-season exploration of the complete output of Johannes Ockeghem; there’s much to explore on their website…. On Friday, March 22, the SEM Ensemble reprises their famous performance of Morton Feldman’s For Philip Guston at their Willow Place headquarters in Brooklyn. I wrote about SEM’s 1995 traversal for the New York Times…. On April 5, Marianne Schroeder, one of the greatest exponents of the brutally otherworldly music of Galina Ustvolskaya, will play the six sonatas at St. Peter’s in NYC, as part of the Blank Forms series.