Top 3 songs to evaluate a system

Great suggestions above.  Looking forward to drilling deep into these.

I'd like to add:

Kansas City Monarch -- Ronnie Earl and the Broadcasters.  Nice saxophone and lively piano riffs distinguish good vs great systems
Hard Day's Night -- Kings Singers.  A textbook reference for imaging and vocal placement
Carole Horn -- Nobody Knows.  This is my go to cut for a front row seat to an amazing female vocal.

Others (honorable mention)
Ambrosia -- Time Waits for No One.  The first 1 minute of this recording is still fun to listen to after all these years (crank it up).
The Beatles -- Martha My Dear.  This is an under-appreciated contribution to The Beatles portfolio.

Also, speaking of The Beatles.  I often use the foot tap from Black Bird to demo/evaluate equipment.  You might be surprised how dramatically better equipment affects the "tonality" of something as simple as a foot tap. 

Excellent thread with some seriously good selections, below are a few of mine: sorry, I can’t leave it at just three 😬

Ezio Bosso, “Under The Trees’ Voices” (Live). If you play this and you do not feel that you are one of the musicians sitting in this hall your system needs some attention. It’s a beautiful piece which deserves many ears to listen to it.

Leonard Cohen/Sharon Robinson, “By the Rivers Dark”. Just stunning in ever respect, get lost in that voice with amazing texture and lyrics. Play loud and make your drivers work for a living.

Bob Dylan, “Man in the Long Black Coat”. Give this a spin because it’s not like the BD you think you know (unless your are a true fan. Great recording and detail. If you’re not in the same room as the band check out your gear.

Chris Stapleton, Death Row. You will know why when you play it (loud)

Bela Fleck and the Flectones, “Flight of the Cosmic Hippo” album & track. If you can’t feel the bass strings vibrate?....

Sade, either; “No Ordinary Love” or “Cherish the Day”, both winners.

Hope you enjoy😃

1) "James Newton Howard & Friends" -   Sheffield Labs #23 Side 1           "SHE"

 2) A Tie between: "The Sheffield Drum Record", Side A - Improvisations           By Jim Keltner, Sheffield Labs #14 (As listed by sls141)
      and
      "The Sheffield Track Record", Sheffield Labs #20- Robbie Buchanan,          James Newton Howard, Lenny Castro, Nathan East, Mike Landau*,          Carlos Vega
 3) Donald Fagen - "The Nightfly" (I.G.Y. - New Frontier - The Nightfly)           and/or "Kamakiriad" (Trans-Island Skyway - Snowbound -On The             Dunes)

Supertramps Hide in your shell. Love how it "builds"
https://youtu.be/ObHjBiaP6Y0

I do the 7.4 version. You are surrounded. This disc is about as good as it gets. Its recorded in Dolby DTS and its recorded excellent. Five thousand watts , Four killer subs, and a complete Legacy system. Chest thump is better than being there. I set volumes at 105-110 db. But it really doesn’t seem overly loud. Just penetrating, and crisp. Problem is, its a two hour concert and whoever your showing it off to absolutely wants NO part of leaving until you have played the entire concert .. Last mans wife said (as she sunk into that couch with a nice drink in her hand) "Am I in heaven? Did I just die and go to heaven? .. Lol

https://www.dailymotion.com/video/x2uu90z

https://youtu.be/2AclvpiMX6A