One of the most talented musicians and songwriters of the late 1960s and early ’70s, Stephen Stills is also a confounding one.

It’s hard to think of an artist who had a better streak of songwriting from 1966-73 while playing with Buffalo Springfield, Crosby Stills & Nash and CSN & Young, followed by a stunning first solo album, an almost-as-good second and a year-and-a-half with the eclectic rock-country-Latin mix of Manassas.

Then decades of ups and downs, a few hints to rival past triumphs but mostly downs. Unfulfilled promise? Perhaps that’s a little harsh. Stills did give us a wealth of creativity during that roughly seven-year span.

Since 2007, Stills has released three albums from his vault, most recordings about 40 years old. And all three are better than anything he’s produced since. First Just Roll Tape, an extraordinary demo of songs he dashed off following a Judy Collins session in New York, several to appear on the first CS&N album.

Then Demos, in a similar vein, from CS&N, with his contributions undoubtedly the highlights. And now Pieces, early Manassas tapes, with some solo work and early jams with members of The Flying Burrito Brothers mixed in, a collection so good it makes one wonder why it’s taken so long for this material to see the light of day.

The group Manassas grew out of Stills’ frustration with CSN&Y and his contacting ultimate rock ‘n roll sidekick Chris Hillman (Byrds, Burritos) to get together and jam in Miami with members of the Burritos post-Gram Parsons.

The tracks from these sessions are mostly at the tail end of Pieces, Panhandle Rag, which shows off Byron Berline on fiddle and Hillman’s blazing mandolin, Uncle Pen — a Bill Monro tune on which Berline takes the vocals — Do You Remember The Americans and Dim Lights, Thick Smoke (And Loud, Loud Music), a Burritos live staple.

All range from country to pure bluegrass with Americans the only one to make it onto one of the two original Manassas albums, Down The Road, in a much different form. Dim Lights, a Joe Maphis tune, is played in a low-key acoustic arrangement, with Hillman prominent in the vocal mix.

Hillman, Berline and  pedal-steel player Al Perkins, who essentially became the lead guitar player of the group, wound up staying to help form Manassas along with percussionist Joe Lala, drummer Dallas Taylor and bassist Calvin Samuels, the rhythm section from CSN&Y, and pianist Paul Harris. The unique mix featured a new approach to electrified country with traces of blues, R&B and Latin influences prominent as evidenced on the self-titled, double-album debut, which quickly went gold.

The centerpiece of this collection comes at the beginning of the disc with three tunes, Witching Hour, dropped from the first album, Sugar Babe, which surfaced on Stills’ second solo album and Lies, a harder rocking version of a Hillman tune from Down The Road.

Witching Hour is classic Stills with a medium, Wooden Ships-tempo in the verse and a double-time chorus that gives way to a haunting release. The track shows off admirable songwriting showcased by the impeccable playing of a band that was capable of serious cooking.

Sugar Babe boasts another stellar Stills melody that hints at fragments of an earlier piece, We Are Not Helpless, from the first solo album. Hillman’s Lies, along with another of his tunes later on the disc Love And Satisfy, shows why Hillman is such a vaulable asset. He plays rhythm guitar, sparkling mandolin, sings harmony but can easily take a lead vocal turn and he writes some outstanding tunes to boot.

Lies is a old-fashioned, rock ‘n roll showcase with Stills taking a wah-wah lead, and Love And Satisfy, which was dropped from Down The Road, an easy-going country-rock tune with an infectious groove and some tasty pedal leads from Perkins.

Others include My Love Is A Gentle Thing, a solo acoustic effort by Stills recorded long after the end of the group, Like A Fox, which again melodically hints at some of his classic songs such as Change Partners and Love The One You’re With, albeit with a much different rhythmic feel than either, Word Game, a segment of a double-time, train rhythm-based song that appeared in acoustic version on Stills 2, and a slice of Latin jamming in Tan Sola Y Triste.

Also in the lineup, Fit To Be Tied an early version of Shuffle Just As Bad, from his third solo work Stills, that is drenched with wah-wah over a heavy blues shuffle, and High And Dry, a slow blues feel complete with verse stops and slide guitar that eventually takes off into a blazing up-tempo section. The album closes in typical Stills style with a solo performance of I Am My Brother, the type of country blues playing that has Stills’ unique acoustic style stamped all over it.

Stills has another release coming later this month from his vault of a more recent vintage, a 2008 live show at Shepherd’s Bush on CD/DVD that features a career-spanning repertoire. Based on his vault releases of the past few years, it likely will be worth checking out.