Bill Frisell has been actively -- some would say obsessively -- exploring the depths and dimensions of American roots music since the release of Nashville in 1997.

His subsequent recordings -- Ghost Town, Gone Just Like a Train, Blues Dream, Good Dog, Happy Man, and The Willies -- were all approaches to the various folk styles that originated on American soil: country, blues, bluegrass, field hollers, jazz, and others.

He has successfully been able to blend, extract, adapt, and otherwise morph one set of music onto another through his own approach to guitar playing -- the song.

More than any other contemporary guitarist, Frisell is driven by the notion of song -- what it entails, both in terms of musical and cultural expression, and what it implies.

On The Intercontinentals, Frisell continues his investigation of American music, but as a way of understanding how it entwines with the folk musics of other nations.

Onboard for this outing are Frisell's longtime collaborators Jenny Scheinman; pedal, dobro, and lap steel guitarist Greg Leisz; as well as Brazilian mega-guitarist and songwriter Vinicius Cantuaria; Macedonian vocalist and oud player Christos Govetas and Malian percussionist and vocalist Sidikki Camara.

Frisell had played with Camara and Malian uber-guitarist Boubacar Traore a couple of years before and was intrigued enough to explore the connection further.

The result of this unlikely union is one of the most seamlessly beautiful works Frisell has ever produced.

On it, he and Cantuaria delve into the modern Malian guitar and percussion sound pioneered by Ali Farka Toure; blend it with the timeless emotional resonance of Greek folk songs via Govetas' oud and infectious Brazilian lyricism; and filter it through shimmering country landscapes and otherworldly string textures that reinvent harmonic properties to suit the lyric of the blues, song, indigenous folk musics, and the contemporary improvisational ideal.

Frisell composed the lion's share of the tunes here, but there are also contributions by Gilberto Gil, Traore, Govetas, and Cantuaria.

Scheinman's violin acts as a gorgeous signpost for virtually all of these musicians to return to; her melodic sensibility and crisp tone are beacons in the often swirling, escalating, and/or cascading whorls of plucked strings, playing as many as four melodies simultaneously with winding, almost knotty scalar interchanges.

What is most fascinating is that even in the vocal tunes, or those where the Malian blues effect is the prominent force, everything else in the mix fans out and creates often contrapuntal backdrops for elegant and lush, if dense, textures.

Simply put, this is the busiest record Frisell has made in years, but it doesn't feel like it.

His sense of "song" is so pervasive, everything here is arranged to fit its "singing." His own tone is unmistakable, as is Leisz's and Cantuaria's.

The guitars are as distinct as the oud and the violin, all of them carried into the next space by hand drums.

While each song does stand on its own as a harmonic and lyrical entity, with adventurous improvisation added in the spirit of true exploration, as an album they are linked by the weave of aural tapestry, dynamics, and spaciousness that is so central to Frisell's sound.

And while this is more collaborative than perhaps anything he's done in a decade, it nonetheless bears his sonic and esthetic imprint.

This is a remarkable album; its sets a new watermark for Frisell's sense of adventure and taste, and displays his perception of beauty in a pronounced, uncompromising, yet wholly accessible way.