I need a way to decrease the volume just in Chrome. The music comes from Google Play Music and there is no volume settings. I'd like to listen to Google Play music and also hear combat effects from a video game (which is running simultaneously). The combat effects volume in the video game is already maxed, but music from Google Chome is much louder. So, I can't find a way to hear both the music and the game sound.
Have you tried using the mixer option,
Left Click on the Speaker that is on the left hand side of your screen near the time, it will give you the speaker volume and a link to Mixer. That is where you will find the volume options for every application that is producing sound, ie chrome. You can only reduce the sound for it there.
In case you don't want to turn down whole Chrome but only one tab (ie., Google Play Music, so other tabs with potential notifications won't be missed) you might like Chrome extension Volume Master: https://chrome.google.com/webstore/detail/volume-master/jghecgabfgfdldnmbfkhmffcabddioke