8:21 "Where am I now?" Like you said, out of existence. In the void of nothing from which all arises. So hard in fact, you landed back in existence in the level.
The Bob-Omb Battlefield remix at 0:41 is by Acid-Notation for anyone who's wondering. Fun fact: The same remix is used in a Geometry Dash level called Slash (as in the punctuation symbol) by GD Colon.
Timestapms where the music gets funny(with instrument): 0:10 - Flute 4:00 - Synth or Marimba 4:13 - Ride (A Part Of Drumkit) 4:30 - Violin 5:13 - It sounds a bit like a Xylophone but I don't get it 5:27 - Synth (I think its a little bit of violin) 6:19 - Synth 6:29 - Synth 6:39 - Drum (I think) 6:54 - Trumpet (I think) 7:23 - Synth (Where did this sound come from) 7:59 - Trumpet 8:56 - Vibraphone 9:27 - Synth (Where did this sound come from) (AGAIN) I'M VERY SORRY IF I'M WRONG, PLEASE CORRECT IT