If you are on windows and don't have audio interface with loopback option and want to record sound directly into Live from Youtube, spotify ....,
Here is a quick solution
First is you need to install Asioflex driver
In this youtube video there is a quick explanation where to find it and how to do it
https://www.youtube.com/watch?v=3eUHSJX2HSY
Asioflex
https://github.com/dechamps/FlexASIO/re ... exasio-1.9
Asioflex GUI
https://github.com/flipswitchingmonkey/ ... I/releases
When starting Asioflex in Live window might popup asking you to install Windowsdesktop runtime, choose install
Once that's done , setup driver and open it in ableton live audio device settings
Then press Hardware Setup, window will popup with Asioflex driver settings
Here you can choose windows driver(Wasapi) Buffer size , Input device (for loopback option) and output device
For Wasapi you can also set channel , when recording into Live and that's it
Just don't forget to turn off monitoring on channel in Live when recording
cheers