can large (>10kVA) industrial transformers be adapted for use as audio trans

not enough info. you would need to know what the input and output voltages are.

Based on their size, would guess they are step down from 480 to 120 or 240vac.

yes, sorry about that.  most are 480 to 120 i believe. the larger ones may be stepped down to 480 from an even higher voltage. i may be barking up the wrong tree but i am imagining that the sheer mass of these transformers may have a soothing effect on the musical datastream

 You would turn them around and connect the secondaries to your AC wall outlet and the primaries to the filter section of a power supply and other words 120 V in and 480 V, or whatever the voltage is, out. You could use that to power some unimaginably large amplifiers. But otherwise, why bother? It’s the turns ratio that limits their usefulness in audio.

You could use a pair of the same type, use the first in reverse, e.g,
120->480 then a second to convert the 480 back to 120. 
This combination would probably give you a cleaner supply, but you have to find somewhere to install 2 large, very heavy transformers :)