Building a 100 album vinyl collection 3 must have albums are?

group 1

Abbey Road - The Beatles

Axis: Bold As Love - Hendrix

Inner Mounting Flame - Mahavishnu Orchestra

group 2

Beggars Banquet - Stones

Dark Side of the Moon - Floyd

Moondance - Van the Man

Group 3

Blue - Joni

American Beauty - The Dead

Blonde On Blonde - Dylan

group 4 (Blues only)

Hoodoo Man Blues - Junior Wells

Paul Butterfield Blues Band - 1st album

Mississippi John Hurt, Today!

Willie Dixon-I Am The Blues

Allman Brothers-Live At The Fillmore East 

Joni Mitchell-Hejira

Sheffield Labs  "I've Got The Music In Me with Thelma Houston and Pressure Cooker",  "Jethro Tull Aqualung,"  "The New York Rock And Soul Review" with Donald Fagen.

Too many to count, so off the top of my head: Donald Fagen “The Nightfly”; The The, “Who’s Next”; Chicago, “Chicago Transit Authority.” Best wishes!

Big Head Todd -- Sister Sweetly 

Art Pepper -- Art Pepper Meets the Rhythm Section

Beethoven's Violin Concerto -- Anne Sophie Mutter