Nothing since a radio telescope isn't a fucking speaker.

the THX intro sound

Darude - sandstorm

There is absolutely only one choice, no need to even think about it it's this.

Darude, Sandstorm

Pump Up The Jam by Technotronic

Let S be an endless string which is a concatenation of every binary counting in succession, starting from zero all the way to infinity (without left zero-padding):

S = 01101110010111011110001001101010111100110111101111...
(from concatenating 0, 1, 10, 11, 100, 101, 110, 111, 1000, 1001, and so far)

Let S' be a set of every sequential group of octets (8 bits) from string S, which can be represented as a base-10 number (between 0 and 255), like so:

S'_2 = [01101110, 01011101, 11100010, 01101010, 11110011, 01111011, ...]
S'_10 = [110, 93, 226, 106, 243, 123, ...]

I'd create an audio wave file whose samples are each octet from S'_10 as 8-bit audio samples, using a really low sampling rate (such as 8000 Hz or even 4000 Hz).
That sound, that particular sound, is what I'd transmit to the cosmos: the binary counting, something with a detectable pattern (although it'd be not so easily recognizable, but something that one could readily distinguish from randomness noise).

"Come here! I will help you conquer this world. Our civilization is no longer capable of solving its own problems. We need your force to intervene."

(Not really, but...)

Prodigy - Diesel Power

Or maybe the brown note. If it was ever going to work it'd be through this.

4′33″

Either Never Gonna Give You Up or Darude - Sandstorm

-The internet (10-15 years ago)

baby shark obv

CBAT. Get the rest of the galaxy in the mood.

Baby Shark

The brown note.

Never gonna give you up

Imperial march

Video killed the radio star

Ram Ranch.

Bullug Gegbug Ibgabiug Gixcure Dagabciea Fuic by Keygen Church because the universe deserves to hear the gospel. Praise the code. https://m.youtube.com/watch?v=iJtVDEx2HSk

Answer in title, unrelated Belgian techno anthem.

Video Killed the Radio (Telescope) Star.

Cotton eye joe

Supernaut

A cover of Black Sabbath's "Supernaut", by Al Jourgensen of Ministry's side-project 1000 Homo DJs with vocals by Nine Inch Nails vocalist Trent Reznor.

free bird solo 🤙

Royalty free Christmas music

Fuck the Pain Away

So What'cha Want by the Beastie Boys

numa numa all day long

Seven Nations Army

Ready to die by Andrew W.K. The song ending with “You just heard earth music. This was a warning.”

Sleep now in the fire

Ok ignoring the fact that this isn't a speaker, if it was and the question is what would I play on a speaker this size, then probably this.

Megalovania

Pink Floyd - Set the Controls for the Heart of the Sun

https://youtu.be/JcfgJrHo9XA

I could think of a few Ministry tracks, but I'll go with N.W.O.
https://youtu.be/imqvLToWH7k?si=QIw2KiyEcSKGgKmf

Goldeneye Surface level PTSD. Enemies beyond your sight horizon due to fog/snow, no map overlay for relative positioning, memorization was the only way to not get lost.

Caramelldansen

War cant of Mars

https://www.youtube.com/watch?v=wy-sVTaZRPk

Kirin J Callinan - Big Enough

Everybody dance now!

Y'all are way too nice. I'm pumping a 60Hz square wave right into that thing at max volume.

Sounds of Beast In Black, if power metal was mixed with Abba, of course!

https://youtu.be/f8qWbowzwZU?feature=shared

I always want to play Queen on my big speakers

"In 2008, RT-70 was used to beam 501 messages at the exoplanet Gliese 581c, in hopes of making contact with extraterrestrial intelligence. The messages should arrive in 2029." - https://en.wikipedia.org/wiki/RT-70?wprov=sfla1

Nice

I mean, if it WAS a speaker?

The Only Thing They Fear Is You.

Skrillex - Bangarang

https://youtu.be/YJVmu6yttiw?si=UyE6XIFBeiDNsWKQ

We Interrupt This Programme
(Yeah, I'm oldschool like that)

He's bouncing off my booty cheeks I love the way he rides. I can hardly breathe when he's pumping deep inside.

Imperial march?

Really gonna hit that 16hz pipe right!

Id freak out about having to make a choice and then just blurt out souvlaki space station because it seems like a safe bet of sm i like at high volumes.

Because boobs- psychostick

brown noise

Sir mix alot baby's got back.

Thanks for the wiki link, OP. You sent me down a pleasing rabbit hole reading about the large radiotelescopes built by the USSR.

And also, completely tangentially, I have nostalgia for playing the very first Destiny game because the environments were designed with those early USSR Deep Space program aesthetics.

ANYWAY YOU WANT IT

THAT’S THE WAY YOU NEED IT

ANYWAY YOU WAAANT IT

*air guitar*

https://youtu.be/BQAKRw6mToA?si=QGOrdDLVOMULA1AR

The only correct answer

Ghetto Supastar https://open.spotify.com/track/31bf9SEOppLU6lQ85d8om6

It would be funny to broadcast corny 80s dance music to aliens, ngl. Hopefully they don't have that Mars Attack physiology that makes their heads explode to jams.