A skin flute is a very special, but not very unique type of flute commonly referred to as a PENIS. Someone who plays the skin flute sucks a lot of cock

Solarpunk is a movement focused on a positive, ecological vision for a future where technology is used for human-centric and ecocentric purposes. It is a literary, artistic and aesthetic sub-genre and is also closely tied to eco-political activism. Solarpunk narratives have a distinctly positive and utopian foundation in contrast to the often dystopian visions found within other "punk" science fiction genres.

a gay man's favorite instrument

A one-holed instrument that plays best with quick hand movements and nimble finger placement.

Cock.

an insturment that many people enjoy playing. Combine with a tromboner and a sexaphone and you will have the best band in the land.

A "skin flute" is a lesser known euphemism for a "penis." Use of the term "skin flute" is the mark of an obviously hip, knowledgeable individual.