Conversation so far:
what's a side project The Twilight Sad worked on?
The Twilight Sad's Guitarist Andy MacFarlane composed the song The Weath-er Is Bad for Semiconductor Films' short film Brilliant Noise

Question: what instrument did he play on that?
Self-contained rewrite: what instrument The Twilight Sad's Guitarist Andy MacFarlane play on The Weath-er Is Bad for Semiconductor Films' short film Brilliant Noise?