Early-bird passes for Rafael Anton Irisarri's Substrata 1.4 festival went on sale on on Monday and as of this morning 13 remain. Substrata—which takes place July 17-20 at Chapel Performance Space—stands out for its lineups that feature some of the world's most interesting and innovative musicians working in minimalism, drone, improv, and ambient music playing live in an acoustically immaculate setting.

The First Tier 3-day pass is $80. Starting May 1, Second Tier 3-day pass price will be $100. Once Substrata announces the full lineup, regular individual tickets will be on sale for $40 per evening. In a press release, Irisarri said, "These passes will only be on sale until April 30th or until we run out (quantity is strictly limited to 50 passes). Once this happens, we'll be announcing the full line-up for edition 1.4, which thus far is looking amazing." This is no idle boast; Irisarri leaked two names to me (which I can't reveal yet; sorry!), and I was kind of stunned. He's going deep with the bookings, as usual. Past Substratas have included sets by Oren Ambarchi, Biosphere, Ken Camden, Eluvium, Nils Frahm, Grouper, Tim Hecker, Loscil, Daniel Menche, Noveller, Pan•American, and Scanner.

You can keep up with Substrata updates here and purchase tickets here.

Irisarri's latest solo album, The Unintentional Sea, is below. He also just released an album titled Yearling with Thomas Meluch under the name Orcas for Germany's Morr Music label.