Alan Gilbert, about to take over the New York Philharmonic, conducted the epic Symphony No. 4 in Boston. Longtime Ives champion Michael Tilson Thomas of the San Francisco Symphony put on a festival in Miami involving his training orchestra, the New World Symphony, and featuring the Concord sonata via the prodigious digits of Jeremy Dent. The Miami series also featured a panel of experts to provide context. Ives is an artist perennially in need of context, of explanations, because he was sailing his own lonely tack: a singular composer who had a long, singular journey to his climactic sonata and symphony.