Top 3 songs to evaluate a system

Fantastic topic, especially because you're asking for specifics

I'll start:

Ives, Overture & March "1776" Nordic 2L recording
Highlight: At least first 1/2 of song. High quality recording with a lot going on; great test of soundstage depth, width, instrument separation, and the ability of a system to deal with very complex transients and dynamics across the entire frequency spectrum.
https://www.discogs.com/release/4195543-Various-The-Nordic-Sound-2L-Audiophile-Reference-Recordings

Shelby Lynne -- Just a Little Lovin' (other tunes from this album also excellent)
Highlight - Thump of bass drum at beginning should shake your room, will test bass response and dynamics from the get go. Instruments have a lot of space, are very well recorded; vocals have a tremendous amount of texture. 

Keith Greeninger & Dayan Kai, Looking for a Home (Blue Coast Collection - The E.S.E. Sessions)
Highlight: Male vocals, acoustic guitar and steel guitar; startlingly lifelike recording, extraordinarily precise soundstage locations for both singers and instruments.

I might suggest a slightly different approach to this question.  It's easy to list great sounding music.  The problem being those picks tend to make most every system sound good.  I would suggest using music that has always seemed flat (for want of a better term) on one system and ask does the next system improve the sound?  Would that not better show the difference?  Just a thought.

Thanks @hilde45 for being the first. I should have added a double bonus to have song easily available.. like Spotify. I can't find two of the thee pieces proposed. But Shelby Lynne is great and it's really my style of music!

@bigtwin - Excellent point, and is indicate that your strategy is to use "flat music" to evaluate a system. Really something to think about. But which flat song do you use?

@papyneau Nordic 2L is pretty easy to find -- take a look here:
https://open.spotify.com/album/78zkF5WPgizHwoeGmPawy5

They also have free downloads

@bigtwin makes an *excellent* point. I'd say doing both (audiophile and flat recordings) is a good idea.

I'd say any system that could make Yoko Ono sound OK, is one heck of a system. Anything she has EVER done as far as singing sounds BAD.

As far as a business women, she ain't no dummy, but she was always hard to look at.. My mom would say "Back that one in Son, park her close to the door". :-)

Highwayman by Johnny Cash
Rainmaker by Strunz & Farah
Da Club by 50 cent or Havana by Camila Cabello

They tell me what ever I'm going to listen to is going to sound good or NOT.

Rainmaker is my cable, cap, resistor, tube, tester. :-)

Regards