That could be done, and the lights would work OK, but you might find some unwelcome hums coming out of your expensive audio equipment!If you were to use single cables in conduit (as opposed to twin and earth) you could have Line(live) looped at the switch and Neutral looped at the lights.
You may regret not having the provision for a neutral there, should you need to put a photocell/PIR there in the future.Is it likely to be an issue in your opinion?
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