"Micro-operas" and monster drone epics share billings in this ambitious new-music festival. It begins on Saturday with the 10-hour "Day Trip," a sound installation and performance by the composer Adrian Knight with the percussion ensemble Tigue. From noon to 10 p.m., audiences are welcome to wander in and out or immerse themselves in its time-bending entirety. A full schedule for the festival, which continues through March 5, is at avantmedia.org.