Is there a way to tell OS X I want my music player to play over Airplay but Chrome to play on my computer's speakers at the same time?
I have a hunch it's possible because some apps let me switch (I can choose to have my VoIP calls output to the computer's speakers while all the rest of the audio plays through Airplay) but is there a way to control this globally whether the app has an option for it or not?
Hijack Pro seems to be doing it but it costs 50$ and seems to be overkill for what I want to do.
Best Answer
Soundflower used to be the thing for that kind of task, but it's fallen by the wayside a bit over the past few years.
It was originally by Cycling 74, but then Rogue Amoeba took over the hosting. They never did anything further with it & eventually it was open sourced & a couple of newer versions were produced.
The latest I'm aware of is a signed v2.0 beta at https://github.com/mattingalls/Soundflower/releases though I've not tried it myself since the older 1.6.x versions started to fail on Mavericks.
Your fully-flexible & El Capitan-compliant alternative is, as you discovered, Audio Hijack - which is extremely good at what it does, but is pricey for a one-trick pony.
See https://apple.stackexchange.com/a/203009/85275 for some configuration examples.