In 1966, Van Morrison was a rough-and-tumble blues singer with the rowdy Belfast band Them.

In 1968, Morrison was a solo artist who created a genre-defying, visionary masterpiece with his album Astral Weeks.

Clearly a great deal happened during the time in between, and arguably the most important thing was Morrison reconnecting with songwriter and producer Bert Berns, who had worked with Them.

Berns understood Morrison had tremendous talent and potential, and when he learned than Van had left Them, Bert invited him to come to New York City and cut some solo material for his label, Bang Records.

A few months later, Morrison had his first solo hit, "Brown Eyed Girl," and his first quarrel with the music industry when the material he cut for Berns was compiled into an album, Blowin' Your Mind!, without his consent.

While Morrison's material for Bang has been collected in many different forms, 2017's The Authorized Bang Collection is the first time anyone has done so with Van's participation and approval, and if it's not quite revelatory in its presentation (most of this material has been widely available before), it's certainly definitive in its quality.

The first disc features the 17 Morrison tracks that Bang released as singles and on the albums Blowin' Your Mind!, The Best of Van Morrison (despite the title, most of it was unreleased), and T.B.

Sheets, while disc two is devoted to single edits and session outtakes.

While the material on the second disc is clearly for completists and hardcore fans, the tracks offer a fascinating look into the way Berns' production style complemented Morrison's loose but impassioned working methods in the studio.

Berns was willing to create a spontaneous environment where the musicians served Morrison's vision, and it's not at all hard to see how tracks like "T.B.

Sheets," "He Ain't Give You None," and "Send Your Mind" set the stage for the poetic conceits of Astral Weeks (especially given the presence of an early version of "Madame George").

The crisp new remastering of the original mixes shows Berns got a tough, lively sound out of his studio band, and the interaction between Morrison and the players is even more impressive with this set's new clarity.

And closing out the collection is the first official release of the infamous set of demos Morrison cut to get out of his Bang contract.

These songs were clearly meant to be too bad to be released, but it's all but impossible not to be fascinated as Van improvises spirited nonsense like "Ring Worm," "Up Your Mind," "Here Comes Dumb George," and "Want a Danish" over the space of 36 minutes.

Morrison's 1967 work with Bert Berns at Bang was vital as it set the singer and songwriter on his creative path, and The Authorized Bang Collection offers an outstanding look into this annus mirabilis.