yeah, vocals may be great in a psytrance track if they are well done, and fit the atmosphere of the track. The voice has to be nice, like in some Shpongle tracks, and has to add emotions.
Examples of bad vocal psytrance :
Infected mushroom 2 last albums,
Analog pussy - Trance N Roll - Track 03,
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i think there are many things to explore, like Juno reactor did it, and i'd like to hear nice vocals like Dorset perception in a "normal" psytrance track.
btw, I like women vocals much more )
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Interesting topic.