Who is happier when a labor of love turns out to be a beautiful thing, the artist or the listener? Tucson flatpicking guitar whiz Greg Morton has to be satisfied with this indie release, six months in the making; it’s sterlingly produced, cleanly picked and properly sequenced. But just as happy is the unassuming acoustic music fan who finds he is physically incapable of getting When Pigs Fly out of the CD changer. The dang thing has been in there for a month and every time I try to eject it, I give “just one more listen” to whatever cut happens to be lodged in my head.

What a beautiful collection. Call it bluegrass or newgrass if you like – the appearances of Sam Bush and John Cowan, among others, only reinforces that impression, at last cosmetically – but the music is better filed under “American string music” (lest anyone looking for high harmonies and furious fiddles mistakenly stumbles on it). Not that they would necessarily be disappointed: Morton and company pick the heck out of “Billy In The Lowground”, a guitar-vs.-banjo breakdown that’s remarkably tasteful. The same could be said about “Never See My Home Again”, which pits mandolin against the guitar.

“Telluride”, “Fireball” and “Brody’s Bounce” reveal similar, more country-folk flashes of virtuosic dexterity, but the standout is “The Door Into Summer”, with the typically fluid instrumentation supplemented by strong vocals carrying the chorus along on a brace of ascending chords.

For the sheer educational novelty, the antique closer, “Soldier’s Joy”, is prefaced by an explanation as to how it became a traditional: When the Cherokee survivors of the Civil War made it back to the capitol of the Indian Territory, they were met at the edge of town by the band, which struck up this melody, believing the best day a soldier has is the one on which he comes home.

Greg Morton plays “Telluride”, accompanied by Mark Robertson-Tessi.