The Haden Triplets, "The Family Songbook” (Trimeter Records)

On their new album, “The Family Songbook,” The Haden Triplets sustain the longstanding musical tradition of siblings singing in harmony while also expanding their family's musical footprint, which goes back generations.

On the second album they've recorded as a group, Petra, Rachel and Tanya Haden, daughters of legendary jazz bassist Charlie Haden, interpret a wide range of songs.

The selections include not just American folk standards like “Wayfaring Stranger” and “Flee As A Bird,” but a heartbreaker from Kanye West, “Say You Will,” and even a composition from their brother, Josh.

Also aboard are four previously unpublished songs from their grandfather, Carl E. Haden. They may have been sung on the the Haden Family radio show in Missouri in the 1930s, where Dad Charlie got his start as a yodeling toddler, but were not recorded. Their recovery is a real treat.

The four dusted-off works include “Memories of Will Rogers,” an homage to the actor and humorist who died in a 1935 Alaska airplane crash, and the lovely but fatalistic “Who Will You Love.”

But it's not all shimmering vocals, either, as the excellent backing ensemble includes such esteemed players are guitarist Bill Frisell, Greg Leisz on pedal steel, drummer Jay Bellerose, percussionist Joachim Cooder — whose father produced the Haden Triplets 2014 debut — and bass players David Piltch and Larry Taylor, among others.

While harmonies dominate but there are occasional solo spots, like on the magical “Every Time I Try,” written by brother Josh, which also features some excellent guitar work from Doyle Bramhall II.

The sisters' natural empathy really shines through across the album, produced by Woody Jackson, and the songs from their grandfather are a shining addition to the family treasure chest.