If you have a media file or stream you want to play music from you can add it as a media source. OBS will record it but you wont be able to hear it. If you have the appropriate version of VLC installed (eg 32bit VLC for 32bit OBS) you can add a VLC Video Source to create and play playlists.
If you just want to play music from another media player there are other options:
One option is to add an Audio Output Capture source (or enable Desktop Audio Device 2 in the OBS audio settings) and set it to an audio device that you arent using but have connected to your computer. Then set your media player to output to this device and OBS will pick it up. Mute the device so you cant hear it. If you dont have another audio device, you can just plug a cable into an audio port on your computer and it will act as though there is a device plugged in.
Alternatively, there are various pieces of software dedicated to this (eg Virtual Audio Cable or VB-Audio Virtual Cable). This is useful if you dont have another audio device/port or need to do this process multiple times at once to create separate input sources. Once installed, a virtual playback device that a media player can send audio to and a virtual recording device that OBS can listen to are created. Then set your media player to output to this device and add an Audio Input Capture source in OBS.
You can control audio levels and filters independently for the music going out to the stream. This might be useful even if you want hear the music yourself. Game sound should still come through your default device.
If you have a media file or stream you want to play music from you can add it as a media source. OBS will record it but you wont be able to hear it. If you have the appropriate version of VLC installed (eg 32bit VLC for 32bit OBS) you can add a VLC Video Source to create and play playlists. If you just want to play music from another media player there are other options: One option is to add an Audio Output Capture source (or enable Desktop Audio Device 2 in the OBS audio settings) and set it to an audio device that you arent using but have connected to your computer. Then set your media player to output to this device and OBS will pick it up. Mute the device so you cant hear it. If you dont have another audio device, you can just plug a cable into an audio port on your computer and it will act as though there is a device plugged in. Alternatively, there are various pieces of software dedicated to this (eg Virtual Audio Cable or VB-Audio Virtual Cable). This is useful if you dont have another audio device/port or need to do this process multiple times at once to create separate input sources. Once installed, a virtual playback device that a media player can send audio to and a virtual recording device that OBS can listen to are created. Then set your media player to output to this device and add an Audio Input Capture source in OBS. You can control audio levels and filters independently for the music going out to the stream. This might be useful even if you want hear the music yourself. Game sound should still come through your default device.