I like it with no loop. It can be any hour length.
For meditation music via computer…I wouldn’t use YouTube. I actually DO NOT use You Tube.
I’ve found the best meditation music is on Pandora (www.pandora.com). Free or paid. Paid you lose the ads.
May not work for you. Works for a number of the folks I know…
Namaste…
The Relax Channel on youtube has lots of links for this genre of music including this 3 hour meditation music.
I like the music of Carlos Nakai.
Crystal Singing Bowls
Calm.com
Others