What do you actually listen to during a 3AM deadline sprint?

Most focus music is built to be pleasant. That's the wrong design goal.
When I'm debugging at 3AM with a ship deadline in 6 hours, melodic audio pulls my attention. My brain follows the harmonic movement. That's cognitive overhead coming directly out of the budget I need for the problem in front of me.
I've been building a channel specifically around this gap — functional audio engineered for the type of work indie hackers actually do. Not lo-fi. Not ambient wellness. Cold, mechanical tracks with no emotional hooks competing for attention.
Just dropped a 4-hour session for exactly this scenario — late-night deadline sprint, deep coding blocks, bug hunting.
Curious what others use. Is it music, silence, white noise, something else entirely?
Session here if useful: https://www.youtube.com/@builderprotocol