The collaboration between Pat Metheny and Brad Mehldau is something that must have been written in the stars. Fans of both men have wondered if it would ever take place, and the end result on the Nonesuch release of Metheny Mehldau is the confirmation that it was destined. Hyperbole? Put it on and listen before you offer that remark seriously. Of the ten cuts here, eight are duets; the other two feature Mehldau's rhythm section, bassist Larry Grenadier and drummer Jeff Ballard. Metheny wrote seven of these tunes, and Mehldau wrote the other three. Each man's compositional style is evident from the word go. There's the luxurious counterpoint that extends form the haunting melody of "Unrequited." Further, there is the natural extension of rhythm and swing on "Ahmid-6." But the real accomplishment here is the ease with which these men play such sophisticated and engaging music that is, perhaps on paper, difficult. But its expansive sense of lyricism and yes, rhythmic interplay, is continually surprising; there is no competition in these tunes, they flow, one into the other with a language being made on the spot. On the quartet tunes, such as Metheny's "Ring of Life," the influence of postmodern drum'n'bass -- à la electronica -- is heard in the tough breakbeats played by Ballard and the counter-rhythmic invention of both Mehldau and Grenadier. It is Metheny's melodic voice, his continually approaching the euphoric, that holds it all together and makes something utterly moving out of it. The gentle swing of "Say the Brother's Name" (also by Metheny) takes Mehldau's sense of the phrase and expansive left-hand technique as it finds harmonic invention in the middle register as the key to unlocking the track's mystery. Mehldau's typically understated solo splits the seam and allows the genuine intensity of the cut to come through. Rhythmically there are breaks here too, but not as pronounced or as forceful as on the earlier selection. Indeed, when all is said and done, the listener is left wanting -- more that it. One wishes that a double album would have been made, one with the duet -- so full of startling moments it's impossible to list them all -- and quartet, whose genuine sense of extrapolative swing is not only inherent, but infectious.