As others have said, you're on a hiding to nothing trying to get a proper description of a k-hole. Closest I could do is - as others have said - that it's like a dream. Semi-lucid dream sometimes, other times fully lucid. It's all internal though. I suppose there sort of are visuals but not really. Perhaps I could try to briefly describe my first ketamine experience (which was very holey indeedy) a bit as an example...
First thing I noticed (about 10 minutes after a line around 75mg or so) was that it 'looked' (probably closer to an impression than actual visuals - bit like an especially vivid daydream maybe) like one of my walls had become a window onto Mario 64. It was really quite specific about that too. I called then Mrs Shambles in cos suspected she'd be liking this as much as I was starting to (cos ket just feels lovely anyway but got the impression this was gonna get interesting). She joined me with a similar amount and I had another wee top-up.
Next thing we were both sat on the sofa and it hit hard. I was leaning against my ladyfriend and suddenly fell right through her. I know this cos I apologised - 'Sorry, but I just fell right through you', 'That's okay - you were supposed to' (or words to that effect. I had the most extraordinarily vivid sensation of the two of us being a single entity - kinda like we were made of plasticine and got melted together actually. It was pleasant but almost disconcerting. Almost but not really cos it's really quite hard to be concerned about anything on ketamine.
For the rest of the night we were mostly horizontal (impossible to really move when actually k-holed) and experienced back-to-back shared... I'd say more like visions than hallucinations as it's so internal. I had a thing for going underwater but she found it a bit disturbing down there so she took me flying instead. This was all the most natural thing in the world. Only complaint I had was it's so brief (maybe 45 mins or so - an hour absolute tops) but I suspect too much longer and things could get a bit much or you'd never really come back properly. Even with the brevity a gramme lasted both of us around 12h of back-to-back holes - is bloody strong stuff with no tolerance (assuming it has actual ketamine in it as the main (ideally sole) ingredient).
Music is essentially irrelevant as you aren't aware of it (nor anything else that exists in this world) when fully holed. We happened to listen to the KLF all night which created a series of (at the time) rather hilarious connections to do with K-trains choo-chooing along and the like. I was only aware music was playing between lines though.
As far as combos go, stick to small bumps rather than full lines unless absolutely sure what you're doing cos the combined effects can stack exponentially - especially with psychedelics. Save the lines for the tail end of whatever else is involved. As others have said though, don't jump to combos until you get a feel for ket itself. It's such a unique drug that it really deserves to be treated with a bit of respect. It repays in droves - or can (and will) turn on you viciously if piss is taken.
Ive never had ket with acid, id imagine its lovely, with mdma its fantastic.. id also hazard a guess that a 'candyfip' (hate that term) is even better.
Not such a hazardous guess - most definitely works rather well with the MDMA/LSD combo
