Geir Jenssen has moved toward something new on Dropsonde -- finally on CD after having been issued on LP some months previously.

The CD version contains more music, about 25 minutes more.

It's the sound and arrangement of this one that grabs the listener's attention quietly and gently, but nonetheless insistently.

First, the definition that provides a telltale hint of the album's sound: a "dropsonde" is a radiosonde, dropped by parachute from an aircraft, to obtain soundings of the atmosphere below.

The principle applies here in spades.

The opening moments of Dropsonde's second track, "Birds Fly by Flapping Their Wings," are familiar to all of Jenssen's ambient music: a gray sonic wash of random elements that could be weather, water, etc., float in from the margins.

A synth plays a quiet drone underneath for a few moments.

About 40 seconds in, a drum loop that could be from Tony Williams on a Miles Davis record slips in.

It's constant, it never moves, but it shimmers just right for the two-chord keyboard sequence to hover above while the other sounds and keyboards subtly move in ghostly fashion through the middle and underneath.

The rhythm is hypnotic, but the piece is far from static -- it just slowly draws you in.

There is emotion in it; it feels good; it feels meditative but alive.

The piece gradually strips away everything but the sounds the listener heard coming in.

The Miles reference isn't a mistake; in a number of tracks here, Jenssen touches upon the jazz musician's colors, modes, tensions, and edgelessness.

It's the Miles of the second quintet and the Miles of In a Silent Way, where mode falls away and the smaller, repetitive vamp leads the way in.

Check "Triple Time," "Fall in, Fall Out" (with its shimmering, authoritative military-style loop), and "Arafura," which is perhaps the finest articulation of Jenssen's method; it's spare and beautiful yet lush, with slowly unfolding mystery.

Other tracks here, such as "Daphnis 26," offer a more forbidding ambient tone before the loops kick in and send the listener to an edge that never quite materializes.

"Altostratus" and the opener, "Dissolving Clouds," are far more minimal, almost random in their computer tones and tunnels.

The blissed-out "Sherbrooke" is a minor masterpiece, taking the ambient form into new directions with its utilization of sonic loops that become rhythmic statements under the radar.

The album closes with the whispering quietude of "People Are Friendly," with keyboards swelling gently in hushed tones as voices appear and disappear through the mix for the entire ten and a half minutes before the album itself, like the track, disappears into silence, echoing memorably but indescribably in the mind of the listener.

Jenssen only records when he has something new to say; he's said it here.