Otto Sidharta is an Indonesian composer who has studied experimental composition all around the world for decades.  His new LP on Sub Rosa, Kajang, is a drone and ambient-focused work, with manipulated acoustic timbres.  It contains four lengthy pieces created at different points since 2015.  Various instruments are made to sustain tones infinitely with seamless use of delay and loop points.

The titular "Kajang" (from 2018) initially sounds like an orchestral chord, and gradually swells and slowly morphs into a tone dominated by voice and flute.  The effect is meditative, focused and intentional, without any sound that could distract from the overall pulsing, shimmering harmony.  There isn't much of a low end, with all of the sound taking place in the upper midrange, where a violin would be playing.  This piece is more cohesively tonal than a lot of freeform drone I've heard, with all of the instrumental recordings decisely playing the same pitch as they fade into each other, with a sort of group detune effect used for dramatic flair.

The 2nd piece "Kerikil" (from 2020) is heady bass-driven dark ambience, with rain stick-esque rattling and groaning over a thick undulating low-end resonance.  Field recordings of steps down a rocky mountain path emerge as the middle of the track approaches.  The sparse, abstract emptiness of this track is a huge contrast from the first, which was layered with what felt like an entire orchestra of players.  That track was like an expressive wash of emotional colors, where this one is like a trip to the moon.

"Len" (from 2015) is a cold and eerie semi-melodic resonance, seeming impossibly distant, like a sound obscured by hundreds of feet of water.  There is a rapid aggressive tapping like rain on a metal roof, as well as distorted voices as heard over a radio.  This ominous and chaotic track brings me back to vintage musique concrete and the 80's works of Nurse With Wound.  A little bit of the euphoric, ethereal energy of the first piece comes back in the warm pads in the 2nd half.  The disconnected underwater feeling continues with the final piece, "Pass" (from 2017).

Rather than feeling like a themed album, each of Sidharta's four long pieces feel very much like separate, self-contained works.  The first and second tracks, in particular, strive for almost opposite aesthetics, but make perfect sense as individual environments.  As he likes, he switches between melodic instrumental drones, field recordings and carefully processed and textured noise.  The warm tunefulness of the first piece is never fully revisited in any of the other three pieces, with much of this collection taking on a subterranean, vaguely ominous energy.  All of the work here is well-produced and texturally rich, but the overall album construction is a bit anti-climactic, with the most dramatic material at the beginning. To find out more for yourself