Ever since Keith Rowe’s renowned deployment of the portable radio as a tool for abstract music, the family of devices has become somewhat of a staple in the arsenal of junk-drawer-diving improvised acts, but it’s rare to see it totally isolated. Aki Onda experiments with a prolonged capture that’s almost voyeuristic (A Method to Its Messiness), Daniel J. Gregory promotes it to both a producer of emphasized sound events and simply a piece of its environment (Heard Under Orphan Eyelid), and Alyssa Festa (a project now sadly defunct) plays with primordial beeps and background noise, yet none of the three rely as heavily on the compositional possibilities of real-time channel surfing, or at least certainly not as much as Promise Garden Frequency. Freshly released by what appears to be some new evolution of the prolific 7Form netlabel project, this digital-only album from Grounded is a murky, unpredictable, even hallucinatory descent into the fragile space of dead air, fragmented broadcasts, and jarring stylistic contrast. The 15-track suite plays like a single piece, evolving from live dial-scrubbing at first to accommodate increasingly complex layers; these post-recording interventions aren’t concealed or hidden in any way, but their presence doesn’t affect the half-exhilarating, half-sedating effect of the almost omnipresent frequency jumping. The artist’s well-tuned ear and hand coax a variety of significant emotional resonance: dazed catharsis in “Rationalise Stems”; dread and darkness in the densely packed static of “Sinking Deeper and Deeper”; electric anxiety in “Ringing Deep Now”; queasy, uneasy grandiosity in “Derelict Garden.” Promise Garden Frequency is a truly “plundered” release, much more so than most who claim the label for themselves, and is enthralling in both its stretches of atmospheric broodiness (“A Way Out”) and sublime pop-chop ecstasy (“Because I Am”).