A more complete list of albums released in 1971. For some releases, I couldn't find the exact date, only the month.
JANUARY
Little Feat: first album JAN
Chicago: Chicago III JAN 11
Janis Joplin: Pearl JAN 11
FEBRUARY
Faces: Long Player FEB
Carole King: Tapestry FEB 10
Yes: The Yes Album FEB 19
MARCH
Johnny Winter And: Live MAR 2
Uriah Heep: Salisbury MAR 8
Alice Cooper: Love it to Death MAR 9
James Taylor: Mud Slide Slim and the Blue Horizon MAR 16
Jethro Tull: Aqualung MAR 19
APRIL
James Gang: Thirds APRIL
Elton John: 11-17-70 APRIL 9
The Doors: L.A. Woman APRIL 19
The Rolling Stones: Sticky Fingers APRIL 23
The Doobie Brothers: first album APRIL 30
MAY
Gordon Lightfoot: Summer Side of Life MAY
Paul McCartney: Ram MAY 17
Marvin Gaye: What’s Going On MAY 21
Rory Gallagher: first album MAY 23
Rod Stewart: Every Picture Tells a Story MAY 28
JUNE
Blood, Sweat & Tears: BS&T4 JUNE
ELP: Tarkus JUNE 14
Bonnie Raitt: first album JUNE 15
Randy Newman: Live JUNE 20
Joni Mitchell: Blue JUNE 22
Todd Rundgren: Runt - The Ballad of Todd Rundgren JUNE 24
JULY
Allman Brothers: At the Fillmore East. JULY
The Guess Who: So Long Bannatyne JULY
Deep Purple: Fireball JULY 9
Procol Harum: Broken Barricades JULY 11
Funkadelic: Maggot Brain JULY 12
Black Sabbath: Masters of Reality JULY 21
Moody Blues: Every Good Boy Deserves Favour JULY 23
AUGUST
The Firesign Theatre: I Think We’re All Bozos On This Bus AUG
Frank Zappa & The Mothers of Invention: Fillmore East, June 1971 AUG 2
The Who: Who’s Next AUG 14 (UK) AUG 25 (US/CAN)
SEPTEMBER
Bee Gees: Trafalgar SEPT
James Gang: Live in Concert SEPT
Jefferson Airplane: Bark SEPT
Steve Miller Band: Rock Love SEPT
Savoy Brown: Street Corner Talking SEPT
Traffic: Welcome to the Canteen SEPT
Fleetwood Mac: Future Games SEPT 3
John Lennon: Imagine SEPT 9
The Band: Cahoots SEPT 15
T. Rex: Electric Warrior SEPT 27
Three Dog Night: Harmony SEPT 30
OCTOBER
John Prine: first album OCT 1
Frank Zappa & The Mothers of Invention: 200 Motels OCT 4
Van Morrison: Tupelo Honey OCT 15
Ten Years After: A Space in Time OCT 18
NOVEMBER
ELP: Pictures at an Exhibition NOV
Humble Pie: Performance - Rockin’ the Fillmore NOV
Harry Nilsson: Nilsson Schmilsson NOV
Steppenwolf: For Ladies Only NOV
Traffic: The Low Spark of High Heeled Boys NOV
Billy Joel: Cold Spring Harbor NOV 1
Elton John: Madman Across the Water NOV 5
Led Zeppelin: IV NOV 8
Uriah Heep: Look at Yourself NOV 8
Genesis: Nursery Cryme NOV 12
Sly & The Family Stone: There’s a Riot Goin’ On NOV 20
Yes: Fragile NOV 26
Alice Cooper: Killer NOV 27
Rory Gallagher: Deuce NOV 28
DECEMBER
Electric Light Orchestra: first album DEC 3
King Crimson: Islands DEC 3
Paul McCartney: Wild Life DEC 7
David Bowie: Hunky Dory DEC 17