This week the Australian Chamber Orchestra gives the first performances of Horizon, a diptych of two 20-minute pieces — “Visible Horizon” and “True Horizon”— which the ACO is performing on alternate concerts while on tour around Australia.

In April the orchestra will tour North America, including a performance at Carnegie Hall that will be the first time both movements of Horizon will be heard on the same concert. The second half of that program is Schubert’s “Death and the Maiden.”

This year also marks the 100th birthday of the immortal Morton Feldman. And with all this in mind, I’ve written this new essay.

The ACO’s sparkling performance of Horizon will be released in April on Cold Blue Music and ABC Classics.