Help me build up a jazz album collection. Can you suggest a must have album?

Duke Ellington, The Great Paris Concert. Someone mentioned Modern Jazz Quartet at Carnegie Hall. 

There are a couple of boxed sets on Pablo that I love, everyone who was anyone during those times was there. Great recordings too.
Montreux '77: The Art Of The Jam Session, and
Montreux '77: The Collection
 

The ECM label specializes in very cerebral jazz, well recorded. 

As mentioned, a lot of great Blue Notes have been re-issued. 

By just listening to LPs, you are blocking out the greats of today. If you like female jazz singers, there are a bunch. This list seems unaccountably unfriendly to current African American singers such as Samara Joy, Cecile McLorin Salvant, and  Corinne Bailey Rae, but it's a start.

https://www.radioart.com/blog/today-s-remarkable-female-jazz-singers

Some albums I've owned for years and revisit from time to time:

McCoy Tyner's Focal Point & Fly With The Wind

Buena Vista Social Club - eponymous album

Afro-Cuban All Stars - A Toda Cuba le Gusta

Herbie Hancock - Takin' Off

Bill Evans - Portrait in Jazz & Sunday At The Village Vanguard

Oliver Nelson - Blues and the Abstract Truth

Any early recordings by Thelonius Monk and John Coltrain

Modern Jazz Quartet 

Off beat suggestion: Lou Stein (many albums with him playing backup; his solo vinyl is long out of print)

Ella Fitzgerald, Sarah Vaughn, Dakota Staton, Ruth Brown

You can use Tidal (for example) to recommend music related to these suggestions which will undoubtedly help you uncover more gems.

Hardly a mention here of Count Basie. While best known as leader of his big band, towards the end of his career he made a number of outstanding small combo albums on the Pablo Label. Look for any that say Basie Jam or Kansas City. Great music and super high quality recordings.

My favorite album unmentioned so far is Mulligan Meets Monk. I read somewhere that Gerry Mulligan was awed at the idea of playing with Monk. But he would only do it they could play together on Monk's masterpiece "Round Midnight." It is probably the most recorded song written by any jazz artist, and this version is as good as any.

Donald Byrd Band & Voices - A New Perspective.

Album Featurette:

https://youtu.be/vUOTlgtu4d0?si=y57p0uhmVgaiaiOU

I have been gradually listening to as many

of these choices as I can on YouTube, Roon, Qobuz and Tidal. I am going to buy

albums of the ones I like. Thanks to

all!!!