While 1981-1983 received some notice through the Dick’s Picks and Dave’s Picks series, that time period in the Grateful Dead’s history isn’t mentioned with the same frequency and reverence as other eras of the band (e.g. ’71-’73, ’76-’78). Re-evaluation of these forgotten years may be needed after making your way through the seminal San Francisco act’s latest box set.

Spread over 17 CDs, In and Out of the Garden: Madison Square Garden ’81, ’82, ’83 features six previously unreleased concerts at the World’s Most Famous Arena — March 9 and 10, 1981; Sept.20 and 21, 1982 and Oct. 11 and 12, 1983. The set takes its title from a line in “St. Stephen,” which the band played live for the first time in four years at the Oct. 11 date.

The material touches upon the three-year period after Go To Heaven came out, when the Dead played more than 200 shows overall. Although there became a seven-year gap between the band’s next studio effort, the members continued to perform new music. In 1982 and ’83, the band performed most of the songs that would appear on 1987’s In The Dark — “Touch of Grey,” “Throwing Stones,” West L.A. Fadeaway,” “Hell in a Bucket” and “My Brother Esau.”

What’s striking and joyous about these particular shows are the unexpected moments that occur on a regular basis before the setlists became more codified in the band’s later years. Here, you can find “Don’t Ease Me In” and “Throwing Stones” not closing a first or second set or “Playing in the Band” and “Wang Dang Doodle” opening shows. Even the undeservedly despised “Keep Your Day Job” makes appearances.

It takes a few moments to adjust to the dry sounding board recordings, and lack of venue atmosphere, from 1981 but it’s something one’s ears get used to as the performances, naturally, take you away. An always welcome “Deep Ellem Blues” arrives on the first night, and while the first set starts off solid enough, it really takes off with a faster than usual “Bird Song” which spreads its wings for 11:15 (11 minutes, 15 seconds) followed by a “New Minglewood Blues” that contains particular bite to close the set. That momentum carries over to the second set opening of “China Cat Sunflower>I Know You Rider” and “Samson and Delilah.”

A similar pattern begins the next night as “Mississippi Half-Step” opens. Matters quickly change when the vibrant “Franklin’s Tower” follows. That momentum doesn’t stop until the double encore of “Satisfaction” and “Brokedown Palace.”

Despite being with the Dead for nearly two years at this point, it’s noticeable on the March 9 and 10 recordings how Brent Mydland’s creative personality, vocal power and colorful keyboard palette energized the band. You especially get a sense of that when his Hammond B3 organ solo takes over “C.C. Rider.” Jerry Garcia feeds off that to push the number further, and, finally, their musical symbiosis unites on keyboards and guitar.

Those who like their live Dead played at a quicker pace will be ecstatic at the fast “Shakedown Street” opener when the band returns to MSG on Sept. 20, 1982. Other first set highlights include “Duprees Diamond Blues” and “It’s All Over Now.”

“Good Time Blues (Never Trust a Woman)” sounds as if the band’s enjoying making their way through this bluesy number. It moves with a swingin’ pace minus the vitriol found in Mydland’s heart-on-his-sleeve performances near the end of his time with the Dead.

During these ’82 shows, at least five future “In the Dark” numbers are played as works in progress.

With surprises still in store, the Oct. 11, 1983 opener “Wang Dang Doodle” abandons the slow-paced blues shuffle so familiar for something that inspires Garcia to tear it up on Tiger, while the next night ended their visit in the Big Apple with the encore debut of The Beatles’ “Revolution.”

The collection also includes detailed liner notes by award-winning music journalist David Fricke, who explores the band’s connection to New York, which began with a free show in 1967 and ended with six nights at MSG — 52 shows altogether at the Garden.

While the Dead’s March 9, 1981 show will be issued separately, I would argue that the best shows of this box set come from the two 1983 concerts. Both the single show and box set are available at www.dead.net.