Theres a report on erowid that describes what he's talking about that's very interesting
Mushrooms - P. cyanescens - Erowid Exp - 'A True Hallucination'
I haven't sung it into existence but i've encountered what i think he's probably talking about. Many metaphors and labels could be used but all of it only dimly approximates describing it..but to me its just like an exteriorization of the mind or imagination, on some non-local quantum level. I've altered visions/experience through sound somewhat but i haven't had it manifest that way yet
first i had some very intense lucid dreams involving it. Often they are of a very bizarre theatrical nature that sort of unfolds by itself into 'it'. Once i recall having a pet spider with the head of yoda, running all over the place using his force powers and light saber
Then i realized i was dreaming, and that its actions were directed by my mind. I interpreted it as being a symbolic representation of the imagination. With some focus, this thing then began to seamlessly morph into whatever i was thinking about..this got exponentially more intense and wierd until it was as if the human imagination, to an intensity previously unknown to exist, was manifesting right in front of me..except "i" was also "it" just as i was watching it. It eventually became a tryptamine-esque spinning tornado of light, love, objects, emotions, events, places, plants, planets, puns, orgasm, etc. that defied reason and description. This has happened in other dreams, and eventually it either just gets so exciting and intense that i'm stirred awake.. or too deep and i loose memory of what happened next- since its too odd to bring back into the monkey mind..or something
I think thought turning to the visible spectrum is also very common with aya, and even just high doses of harmalas. On the latter, i'll often be deep into a sort of day-dream, and then realize that i'm seeing whatever it is i'm imagining, and sometimes it will drift into this sort of object . Usually once i realize all this is going on and open my eyes, the vision fades like a strong after-image. I remember doing something similar as a child. I would lay in bed at night and mentally coax this oily blob out of the distance and bring it into full view as it morphed into countless faces expressing unfathomable emotions. I thought of it as a sort of collective unconscious at the time, although i was only like 9 or 10 and had no idea about jung, so i never told anyone about it. But the overall feel of it is very related to my other experiences
anyways, its funny people don't talk about this stuff more. Terence said that with practice this can be more thoroughly mastered, and that singing these things into existence was a human ability we all have, just under the surface. this sort of thing was central to his thoughts on the whole 2012/concrescence/transformation of humanity thing. Sounds totally batshit crazy, of course! But maybe we'll gain a better idea of what it is he was talking about when his brother dennis's (who heavily influenced 'terences' ideas for decades) new book comes out in the fall